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Optimal Production of Glutathione by Controlling the Specific Growth Rate of Yeast in Fed-Batch Culture

1991; Elsevier BV; Volume: 24; Issue: 12 Linguagem: Inglês

10.1016/b978-0-08-036929-7.50017-6

2589-3653

Hiroshi Shimizu, K Araki, S. Shioya, Eizô Sada,

Advanced Control Systems Optimization

The optimal profile of the specific growth rate was obtained utilizing simple mathematical model in the yeast fed-batch culture. The model was built based on the mass balance around the fed-batch system and relationship between the specific growth rate, μ, and the specific production rate of glutathione, ρ G . Optimal profile of μ was calculated as a bang-bang type one. That is, μ should start from the maximum value, μ max and should be kept at μ max . And then μ should be switched to μ C , that gives a maximum value of ρ G . It has been proved from the maximum principle that switching was once and switching time from μ max to μ C depended on the final required glutathione concentration in the cell. Finally, this ideal profile of μ for the maximum production of glutathione was realized by manipulating the substrate feed rate, and μ could be controlled at the optimal profile given in advance, using the extended Kalman filter and PF(Programmed Controller/ Feedback Compensator) System. As the result, the maximum production of glutathione was accomplished successfully. The control strategy employed here can be applied to the other batch reaction processes.