title: Acid tolerance response is low-pH and late-stationary growth phase inducible in Bacillus cereus TZ415.
abstract: The acid tolerance of foodborne pathogen Bacillus cereus TZ415 was examined. B. cereus was more tolerant to an acid challenge at pH 4.0 when cells were grown at low pH in regulated batch cultures of rich J Broth (JB) medium. The pH-inducible acid tolerance response (ATR) was maximal at pH 5.0, a sublethal growth condition inducing a remarkable cell elongation. During growth at regulated pH 7.0 and 6.0, B. cereus TZ415 became more acid sensitive from lag to stationary growth phase and the acid tolerance of cells reached its maximum level in late-stationary growth phase. The ATR induced at pH 5.5 and 5.0 was not affected by growth phase. Cellular protein profiles were analysed as a function of growth phase and medium pH. The Hemolysin BL (HBL) enterotoxin was only detected when cells were grown at pH 7.0.
authors.affiliation: UMR A408 INRA/Université d'Avignon Sécurité et Qualité des Produits d'Origine Végétale, France.
authors.forename: Michel-Philippe
authors.initials: MP
authors.lastname: Jobin
authors.forename: Thierry
authors.initials: T
authors.lastname: Clavel
authors.forename: Frédéric
authors.initials: F
authors.lastname: Carlin
authors.forename: Philippe
authors.initials: P
authors.lastname: Schmitt
mesh_terms: D001409:Bacillus cereus / Q000254:growth & development* / Q000378:metabolism / Q000502:physiology; D001426:Bacterial Proteins / Q000096:biosynthesis; D015169:Colony Count, Microbial; D003470:Culture Media; D004591:Electrophoresis, Polyacrylamide Gel; D004768:Enterotoxins / Q000096:biosynthesis* / Q000302:isolation & purification; D005516:Food Microbiology; D006863:Hydrogen-Ion Concentration
chemical_list: D001426:Bacterial Proteins; D003470:Culture Media; D004768:Enterotoxins