FIG. 3.

Effect of Ca²⁺-DPA treatment on spore buoyant density. Spores from strains FB111 (cwlJ), PS832 (WT), and FB110 (sleB) were incubated in water or 60 mM Ca²⁺-DPA; the water- and Ca²⁺-DPA-treated spores from each strain were mixed, and the mixture was subjected to equilibrium density centrifugation on a metrizoic acid gradient. The expected positions of dormant (Dor) and germinated (Ger) spores are indicated by vertical bars. The drift in the position of the dormant spores is the result of minor variations in the gradient between experiments.