Modeling sporulation decisions in Bacillus subtilis as optimal evolutionary decision-making

The decision by the bacterium Bacillus subtilis to produce spores has been an area of intense study in the molecular cell biology field. Though mechanisms describing how the decision is made are becoming better understood, the reasons why the decision is made are still nebulous. Spore formation is known to be a survival mechanism, but the circumstances under which it is preferred over other mechanisms have not been carefully examined. In an attempt to address this issue quantitatively, we introduce simple models and a control framework to compare two bacterial survival strategies: sporulation and a simple reduction in metabolic activity. Our findings provide evidence that the decision to sporulate may be the outcome of an underlying optimal control problem to contend with expected future environmental challenges.