Effect of water activity and pH on growth and toxin production by Clostridium botulinum type G.
AUTOR(ES)
Briozzo, J
RESUMO
The combined effect of water activity (aw) and pH on growth and toxin production by Clostridium botulinum type G strain 89 was investigated. The minimum aw at which growth and toxin formation occurred was 0.965, for media in which the pH was adjusted with either sodium chloride or sucrose. The minimum pH (at the optimum aw) for growth and toxin production of C. botulinum type G was found to be 5.6. Optimum conditions for toxin activation were a trypsin concentration of 0.1%, a pH of the medium of 6.5, and an incubation for 45 min at 37 degrees C. These data did not show evidence of heat-labile spores, since a heat shock of 75 degrees C for 10 min did not significantly decrease the spore count of strain 89G in media at pH 7.0 or 5.6. It was frequently observed that cells grown at reduced aw or pH experienced severe morphological changes.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=238971Documentos Relacionados
- Combined Effect of Water Activity and pH on Inhibition of Toxin Production by Clostridium botulinum in Cooked, Vacuum-Packed Potatoes
- Combined effect of water activity and pH on inhibition of toxin production by Clostridium botulinum in cooked, vacuum-packed potatoes.
- Physiology of Toxin Production by Clostridium botulinum Types A and B: III. Effect of pH and Temperature During Incubation on Growth, Autolysis, and Toxin Production
- Clostridium botulinum Type E Toxin: Effect of pH and Method of Purification on Molecular Weight
- Minimal Growth Temperature, Sodium Chloride Tolerance, pH Sensitivity, and Toxin Production of Marine and Terrestrial Strains of Clostridium botulinum Type C