UV222 killing of spores of strains of B. subtilis with defects in possible protective components. Spores of isogenic B. subtilis strains were treated with UV222, and spore survival was measured as described in Materials and Methods. Symbols: ○, PS533 (wild type); ●, PS3328 (cotE); △, PS578 (α− β−); ▲, PS2318 (recA); ■, PS4150 (cotE gerE); □, FB122 (spoVF sleB), prepared with DPA. Data shown are averages from duplicate determinations ± standard deviations in one experiment. This experiment was repeated twice, with the same relative rates of killing of spores of different species seen.