Quantification of the Effects of Salt Stress and Physiological State on Thermotolerance of Bacillus cereus ATCC 10987 and ATCC 14579

• DOI: 10.1128/aem.00780-06
• Publication Date: 2006-09-06T23:18:42Z
• Authors: Heidy M. W. den B...; Marios Mataragas; Roy Moezelaar; Tjakko Abee; Marcel H. Zwietering
• Keywords: Strain (injury); Cereus; Bacillus thuringiensis

ABSTRACT The food-borne pathogen Bacillus cereus can acquire enhanced thermal resistance through multiple mechanisms. Two strains, ATCC 10987 and 14579, were used to quantify the effects of salt stress physiological state on thermotolerance. Cultures exposed increasing concentrations sodium chloride for 30 min, after which their thermotolerance was assessed at 50°C. Linear nonlinear microbial survival models, cover a wide range known inactivation curvatures vegetative cells, fitted data evaluated. Based statistical indices model characteristics, biphasic models with shoulder selected quantification. Each parameter reflected characteristic, both flexible, allowing reduction parameters when certain phenomena not present. Both strains showed preexposure (non)lethal conditions in exponential phase. maximum adaptive response due demonstrated exponential-phase cells comparable effect strains. However, less pronounced transition- stationary-phase cells. distinct tailing strain attributed presence subpopulation spores. existence stable heat-resistant could be either Quantification might instrumental understanding adaptation mechanisms will allow food industry develop more accurate reliable stress-integrated predictive modeling optimize minimal processing conditions.