Optimisation of strain selection in evolutionary continuous culture

ABSTRACT

In this work, we study a minimal time control problem for a perfectly mixed continuous culture with n ≥ 2 species and one limiting resource. The model that we consider includes a mutation factor for the microorganisms. Our aim is to provide optimal feedback control laws to optimise the selection of the species of interest. Thanks to Pontryagin's Principle, we derive optimality conditions on optimal controls and introduce a sub-optimal control law based on a most rapid approach to a singular arc that depends on the initial condition. Using adaptive dynamics theory, we also study a simplified version of this model which allows to introduce a near optimal strategy.

KEYWORDS:

• Process control
• biotechnology
• chemostat model
• optimal feedback
• pontryagin maximum principle
• singular control

Acknowledgment

The authors are grateful to the “FMJH Program Gaspard Monge in optimization and operation research” and would like to thank A. Rapaport and O. Bernard for helpful discussions on the subject.

Disclosure statement

No potential conflict of interest was reported by the authors.