Influence of the feedback loops in the trp operon of B. subtilis on the system dynamic response and noise amplitude

► We model the regulatory pathway to maintain homeostasis of tryptophan in B. subtilis. ► We explore the role of negative feedback loops in the tryptophan operon. ► Enzyme-inhibition loop accelerates the operon response and decreases the noise. ► Attenuation loop increases the sensitivity and enhances the biochemical noise.