Figure 3.

Schaeffer-Fulton staining on ET 138 wild-type and mutants. Cultures used were grown aerobically overnight in LB2 medium at 55°C and subsequently kept at room temperature for 24 h, after which the staining was performed. Pink-stained cells indicate intact cells, whereas spores are green–blue. a strain ET 138 wild-type, in which sporulation is observed. b strain ET 138 ΔldhL, in which sporulation is observed. c Strain ET 138 ΔldhL ΔsigF, where no sporulation is observed due to removal of the sigF gene.