Figure 2: The sporulation and germination cycle of Bacilli and Clostridia. (A) When a vegetative cell of Clostridium or Bacillus reaches the end of the exponential phase of growth can start a developmental process that will end with the formation of a robust and long lasting spore. (B) When the spore finds a propitious environment and specific germinants it can start a process of spore germination and outgrowth that will end with the emergence of the vegetative cell that was encased into the spore shield. The emerged vegetative cell is able to start new rounds of vegetative division to colonize biotic and abiotic surfaces (spore panspermia). See text for further details.