The acid tolerance response of Bacillus cereus ATCC14579 is dependent on culture pH, growth rate and intracellular pH

摘要: The food pathogen Bacillus cereus is likely to encounter acidic environments (i) in when organic acids are added for preservation purposes, and (ii) during the stomachal transit of aliments. In order characterise acid stress response B. ATCC14579, cells were grown chemostat at different pH values (pHo from 9.0 5.5) growth rates (μ 0.1 0.8 h−1), submitted shock 4.0. Cells low pHo adapted media induced a significant tolerance (ATR). ATR was modulated by both μ, μ effect more marked 5.5. Intracellular (pHi) affected μ. At above 6, pHi decreased with decrease increase 5.5, higher compared 6.0, suggesting that mechanisms homeostasis induced. survival required protein neo-synthesis capacity maintain their ΔpH (pHi - pHo). Haemolysin BL non-haemolytic enterotoxin production influenced