Optimal Control of the Enzymatic Lysis of Yeast

In enzymatic lysis of yeast, the lysis of yeast cells is caused by the action of a system consisting primarily of two enzymes, glucanase and protease. The activities of the two enzymes depend on pH, reaching their maxima at different pH levels. The objective is to determine the optimal pH and/or protease inhibitor concentration profiles to maximize protein production. In this work, a first principles model for the lytic reaction mechanism is presented. The resulting dynamic optimization problem is solved by first discretizing the differential equations using orthogonal collocation; then, Successive Quadratic Programming is used to obtain the optimum. The proposed approach yields optimal profiles such that several times increase of the production of proteins in a fed-batch reactor is realized.