11. Conclusions

The advances in computer technology have revolutionized the field of control of bioprocesses, which makes the heart of any modern industrial fermentation. One area where much progress needs to be made is the field of biosensors since they are central to control implementation.

Control of a bioreactor poses a great challenge to an engineer because of their unique dynamics. Multiple steady states, of which some may be unstable, may be exhibited by the continuous reactors. Fedbatch reactor control is even more complicated since the system state continuously changes. Theoretical advances in controls, e.g., optical control theory, adaptive control, and state estimation techniques, have made it possible to implement efficient control systems. Of particular importance are state estimation techniques which compensate for the scarcity of on – line sensors for the fermentation processes. Knowledge – based controllers promise a great deal of hope for the controls of bioprocesses considering the uncertain nature of fermentation processes.