Essentially, sporulation refers to the formation of spores from vegetative cells during unfavorable environmental conditions. As such, it may be described as an adaptive response that allows the organism to survive given adverse conditions (radiation, extreme heat or cold, lack of nutrition etc).

What triggers sporulation?

Interestingly, there are only two determining factors that trigger sporulation: nutrient starvation and cell density. These two triggers lead to activation of the molecular master regulator of sporulation Spo0A by phosphorylation.

During which phase sporulation occurs?

Sporulation is triggered after cells enter the stationary phase in a medium that supports sporulation, and it takes about 8 to 10 h to be completed (13, 14). Central to the decision to enter sporulation is the activation, by phosphorylation, of the response regulator Spo0A.