Figure 6. Capacity of WT or mutant spores to germinate and form colonies.

C. botulinum and C. sporogenes wild type and mutant spore suspensions were enumerated using a haemocytometer and adjusted to a final concentration of ∼1×10⁸ spores/ml. Spores were heat activated (80°C, 15 min), serially diluted in 0.85% saline, and plated in triplicate on to TY agar before anaerobic incubation (37°C, 48 hrs), after which colonies were enumerated. Data presented represent the mean log₁₀ colony-forming units/ml from triplicate plates, with error bars representing the standard deviation of the mean.