Computer control of glutamic acid production based on fuzzy clusterization of culture phases

The reaction mechanism in a microorganism is much more complicated than that of an ordinary chemical reactor. The mechanism is fundamentally programmed by the DNA sequences of the organism involved, which can change from their original situation with time. It is difficult to keep all of the characteristics of a microorganism constant for a long period, and the improvement of strains by genetic engineering and/or screening techniques is often tried in order to improve industrial fermentation processes. As a result, models of a real fermentation process usually work only for a limited period, and it is virtually impossible to construct a comprehensive and robust model. Furthermore, only a few kinds of sensors are available for monitoring the culture states in fermentation processes, and we cannot measure the state inside cells directly. Therefore, a deterministic model for the application to the control or the simulation of fermentation processes cannot easily be constructed.