FIG. 5.

Resistance of spores with or without DPA to heat (A), hydrogen peroxide (B), formaldehyde (C), or UV radiation (D). Spores were either heated at 85°C (○ and ▴) or 70°C (▵) (A), incubated with 0.7 M hydrogen peroxide at room temperature (B), incubated with 0.3 M formaldehyde at room temperature (C), or UV irradiated at 150 J/m² · min (D), and the survival was measured as described in Materials and Methods. Symbols: ○, Δger3 spores; ▵, Δger3 spoVF spores; ▴, Δger3 spoVF spores prepared with DPA. All experiments were repeated at least twice with essentially identical results.