FIG. 6.

(A and B) Germination of C. perfringens spores with Ca-DPA. (A) Heat-activated C. perfringens spores of strains SM101 (wild-type) (▪), DPS107 (sleC) (▵), DPS109 (sleM) (○), and DPS110 (sleC sleM) (□) were germinated with 50 mM Ca-DPA, and the OD₆₀₀ was measured as described in Materials and Methods. (B) Heat-activated spores of C. perfringens strains were germinated with 50 mM Ca-DPA (░⃞) and 25 mM Tris-HCl buffer (pH 8.0) (□) for 1 h, and the DPA remaining in the spores was measured as described in Materials and Methods. The data represent the average of two independent experiments with two different spore preparations, and error bars indicate the standard deviations.