B. subtilis is capable of forming endospores. This process begins with the cell deciding that the stresses it is being exposed to are too strong for survival, and so spore formation must commence.
The first stage is duplication of chromosomal DNA. The cell then partitions its internal membrane into two, using DNA translocase to ensure each division has all the required DNA.
The forespore, which will ultimately become the spore, is engulfed by the mother cell (giving the forespore 2 membranes). The mother cell then applies a thick cortex of peptidoglycan to the spore, reducing transport into the core of the spore.
The exosporangium is then synthesised (by the mother cell) and coats the spore. DPA (dipicolonic acid) and DNA coating proteins are inserted into the spore, helping to compact the DNA further and protect it from chemical and radiation damage.
The mother cell now degrades and the spore is released.