Coupling of a neural filter and a neural controller for improvement of fermentation performance

The noise associated with fermentation processes is normally minimised by a filtering technique. However, sometimes the noise may be beneficial if it is properly regulated. For recombinant -galactosidase production in a fed-batch fermentation subject to Gaussian disturbances, it is shown that a neural network trained to act as a noise filter can allow disturbances of only a particular variance which maximizes -galactosidase synthesis. By coupling such a filter with a neural controller, the productivity may be enhanced beyond what is possible with static filtering and either proportional-integral-derivative or neural control.