Fig 6.

LtaS1 and LtaS2 are required for spore formation. (A) Sporulation efficiency of wild-type and mutant strains grown in modified G medium for 24 or 72 h and reported as percentage of heat-resistant organisms over total organisms (non-heat treated). Aliquots of cultures were removed at the indicated times, treated or not at 65°C, and plated on solid medium for enumeration of CFU. (B) Spore formation visualized by transmission electron microscopy following 16, 40, and 136 h of incubation of bacteria in modified G medium (WT, ltaS1 ltaS2 pJK4 [double mutant carrying the empty vector], and ltaS1 ltaS2 pltaS2 [complemented strain]).