A predictive model of growth from spores of non-proteolytic Clostridium botulinum in the presence of different CO2concentrations as influenced by chill temperature, pH and NaCl Original Research Article

In the present study, the effect of modified atmospheres ranging from 0–90% CO2(balance 10% H2and N2) was evaluated on growth from spores of non-proteolyticClostridium botulinum (types B, E and F), at different pH and NaCl concentrations, over the temperature range 5–12°C. Growth tests were carried out using a model broth system, PYGS (peptone, yeast, glucose, starch). In general terms, a CO2concentration of 5% enhanced growth, 50% CO2showed a moderate inhibition and 90% had a considerable inhibitory effect. A predictive model has been developed that describes the effect of CO2, in combination with other mild preservative factors, on growth from spores of non-proteolytic C. botulinum. The model provides a good description of the experimental data.