This work shows a class of nonlinear controller implemented to a nonlinear switched system, which describes dynamics of a bioreactor subjected to switching conditions on kinetics. The proposed controller was implemented to a continuous stirred anaerobic bioreactor whose model is derived by classic mass balances and where a sulfate-reducing process took place and kinetic regime alteration is induced. The closed-loop stability of the system is shown via Lyapunov functions and in face to distinct kinetic and transition stages. Numerical simulations were performed to compare the proposed controller to a high order sliding mode controller. The control output is capable of making the sulfate concentration converge to the given set-point, regardless the kinetic regime or transition stage it was on.