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

Abstract

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.