Simulating the migration and growth patterns of Bacillus subtilis

We introduce a cellular-automaton based model for the description of the migration and growth patterns of colonies of Bacillus subtilis. The two phases, associated with processes of migration and proliferation, are described by appropriate rules for the update of the automaton. We show that it is possible to reproduce the patterns present in the morphological diagram for B. subtilis and in particular the ring-like structure that the colonies adopt in the case of a not very hard medium and under nutrient abundance.