FIG 5 .

Spore formation, germination, spo0A gene transcription, and Spo0A production by CN3718, CN3718::codY, and CN3718comp. (A) Heat-resistant spore formation by CN3718, CN3718::codY, and CN3718comp. The bacteria were grown in DS or SFP medium overnight at 37°C; the overnight cultures were then heat shocked for 20 min at 70°C. After a 10-fold serial dilution with distilled water, the heat-shocked cultures were then plated onto BHI agar plates and grown overnight at 37°C for colony counting. **, P < 0.001 (Student’s t test, compared to the wild type). All experiments were repeated three times, and mean values (log₁₀ scale) are shown. The error bars indicate standard deviations. (B) RT-PCR analyses for spo0A transcription by CN3718, CN3718::codY, and CN3718comp grown for 5 h in DS or SFP medium. The leftmost lane shows a 100-bp DNA ladder. (Top) Samples lacking reverse transcriptase to demonstrate the absence of DNA contamination. (Bottom) Samples receiving reverse transcriptase. (C) Western blot analyses for Spo0A production by CN3718, CN3718::codY, and CN3718comp using a 5-h DS medium culture or SFP medium culture cell pellet. The protein size is at left. (D) Germination of spores of CN3718, CN3718::codY, and CN3718comp in BHI broth. Heat-activated spores were incubated at 40°C in BHI broth, and each OD₆₀₀ was measured as described in Materials and Methods. All experiments were repeated three times, and mean values are shown. The error bars indicate standard deviations.