title: Optimal control analysis of the dynamic growth behavior of microorganisms.
abstract: Understanding the growth behavior of microorganisms using modeling and optimization techniques is an active area of research in the fields of biochemical engineering and systems biology. In this paper, we propose a general modeling framework, based on Monod model, to model the growth of microorganisms. Utilizing the general framework, we formulate an optimal control problem with the objective of maximizing a long-term cellular goal and solve it analytically under various constraints for the growth of microorganisms in a two substrate batch environment. We investigate the relation between long term and short term cellular goals and show that the objective of maximizing cellular concentration at a fixed final time is equivalent to maximization of instantaneous growth rate. We then establish the mathematical connection between the generalized framework and optimal and cybernetic modeling frameworks and derive generalized governing dynamic equations for optimal and cybernetic models. We finally illustrate the influence of various constraints in the cybernetic modeling framework on the optimal growth behavior of microorganisms by solving several dynamic optimization problems using genetic algorithms.
authors.affiliation: Department of Chemical Engineering, Indian Institute of Science, Bangalore 560012, India.
authors.forename: Aravinda R
authors.initials: AR
authors.lastname: Mandli
authors.affiliation: Department of Chemical Engineering, Indian Institute of Science, Bangalore 560012, India. Electronic address: modak@chemeng.iisc.ernet.in.
authors.forename: Jayant M
authors.initials: JM
authors.lastname: Modak
mesh_terms: D018407:Bacterial Physiological Phenomena; D003491:Cybernetics; D006128:Growth; D008954:Models, Biological
keywords: Adjoint variable; Cybernetic model; Genetic algorithm; Monod kinetics; Optimal control; Optimal model