FIG. 5.

l-Alanine and dodecylamine germination of spores from the lower band on equilibrium density gradients from heat-treated spores. Ninety-seven percent of strain PS533 spores (wild type) were killed by moist heat at 87 to 90°C, and these spores were fractionated by equilibrium density gradient centrifugation. The spores in the lower band and untreated spores were germinated with l-alanine or dodecylamine, and spore germination was quantitated by measuring DPA release as described in Materials and Methods. (A) l-Alanine germination of untreated spores (○) or spores from the lower band (•). (B) Dodecylamine germination with either 0.25 mM dodecylamine at 45°C (circles) or 1 mM dodecylamine at 50°C (triangles) of untreated spores (open symbols) or spores from the lower band (filled symbols).