FIG. 3.

Germination of superdormant and initial spores with Ca-DPA (A and B) or dodecylamine (C and D). Spores of B. subtilis strains PS533 (wild type) and FB22 (ΔgerA gerBA*) (A and C) or B. megaterium (B and D) were germinated with either Ca-DPA or dodecylamine, and germination was followed as described in Materials and Methods. The superdormant PS533, FB22, and B. megaterium spores were isolated by germination with valine, asparagine-glucose, or glucose, respectively. (A and C) ○ and •, PS533 spores; ▵ and ▴, FB22 spores. (B and D) ○ and •, B. megaterium spores. In all panels, ○ and ▵ indicate superdormant spores, and • and ▴ represent initial dormant spores. It was notable in the experiments using dodecylamine as a germinant that both initial and superdormant spores had essentially identical (within 15%) DPA levels as determined by the amount of OD₂₇₀-absorbing material released from spores (data not shown).