(a and b) Germination of populations of spores of various B. subtilis strains at 25°C (a) and 45°C (b) in response to the addition of l-alanine. Spores of B. subtilis PS533 (wild-type) (●), FB62 (gerD) (♦), PS3411 (↑SpoVA) (■), PS3640 (spoVA1) (▴), and PS3642 (spoVA2) (▾) germinated in response to the addition of l-alanine, and the percent germination was determined as described in Materials and Methods.