Low-pH activation of Bacillus cereus spores.
Heat activation of bacterial spores at low pH was investigated in detail. Unlike activation of spores in distilled water at a neutral pH, activation at low pH involves two superimposed processes: enhanced activation and death. Low-pH-activated spores failed to germinate in d-alanine, in contrast to spores activated at neutral pH, owing to the abolition of alanine-racemase activity. Morphological and permeability changes such as release and partial disruption of spores were dipicolinic acid-observed during low-pH activation. The kinetics pattern of low-pH activation, as well as the change in properties of the spores thereafter, suggest that the mechanism of low-pH activation differs from that of other kinds of heat-activation.
D000409:Alanine / Q000378:metabolism / Q000494:pharmacology; D001409:Bacillus cereus / Q000032:analysis / Q000201:enzymology / Q000378:metabolism*; D005990:Glycerol / Q000494:pharmacology; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D007535:Isomerases / Q000378:metabolism; D007700:Kinetics; D010539:Permeability; D010848:Picolinic Acids / Q000032:analysis; D013170:Spores / Q000378:metabolism*
D010848:Picolinic Acids; D007535:Isomerases; D000409:Alanine; D005990:Glycerol