<p>The key to a robust life system is to ensure that each cell population is maintained in an appropriate state. In this work, a mathematical model is used to investigate the control of the switching between the migrating and non-migrating states of the <i>Bacillus subtilis</i> cell population. In this case, the motile cells and matrix producers are the predominant cell types in the migrating cell population and non-migrating state, respectively, and can be suitably controlled according to the environmental conditions and cell density information. A minimal smooth model consisting of four ordinary differential equations is used as the mathematical model to control the <i>B. subtilis</i> cell types. Furthermore, the necessary and sufficient conditions for the hysteresis, which pertains to the change in the pheromone concentration, are clarified. In general, the hysteretic control of the cell state enables stable switching between the migrating and growth states of the <i>B. subtilis</i> cell population, thereby facilitating the biofilm life cycle. The results of corresponding culture experiments are examined, and the obtained corollaries are used to develop a model to input environmental conditions, especially, the external pH. On this basis, the environmental conditions are incorporated in a simulation model for the cell type control. In combination with a mathematical model of the cell population dynamics, a prediction model for colony growth involving multiple cell states, including concentric circular colonies of <i>B. subtilis</i>, can be established.</p>