In the first part of the talk, I will be explaining how the subtle interplay of dynamics and stochasticicity pervades the phenotype of wild-type bacterium Bacillus subtiliis. In the second part of the talk, I will be focusing on the behavior of an evolutionary plausible mutant recently studied. I will show how nonlinear dynamics and stochasticity collaborate closely to implement phenotype, and how the topology of the core regulatory circuit correlates to experimental observables.