Modeling enzyme controlled metabolic networks in rapidly changing environments by robust optimization

Author(s)
Henning Lindhorst, Sergio Lucia, Rolf Findeisen, Steffen Waldherr
Abstract

Constraint-based methods, such as the flux balance analysis (FBA), are widely used to model cellular growth processes without relying on knowledge of regulatory features. Regulation is instead substituted by an optimization problem to maximize a biological objective such as biomass accumulation. A recent extension to these methods is called dynamic enzyme-cost FBA (deFBA). This fully dynamic modeling method allows to predict optimal enzyme levels and reaction fluxes under changing environmental conditions. However, this method was designed for well-defined deterministic settings in which dynamics of the environment are exactly known. In this letter, we present a theoretical framework called the robust deFBA which extends the deFBA to handle uncertainty in nutrient availability. We achieve this by combining deFBA with multi-stage model predictive control which explicitly captures the evolution of uncertainty by a scenario tree. The resulting method is capable of predicting robust optimal gene expression levels for rapidly changing environments. We apply these algorithms to a model of the core metabolic process in bacteria under alternating oxygen availability.

Organisation(s)
Functional and Evolutionary Ecology
External organisation(s)
Otto-von-Guericke-Universität Magdeburg, Technische Universität Berlin, Katholieke Universiteit Leuven
Journal
IEEE Control Systems Letters
Volume
3
Pages
248-253
No. of pages
6
ISSN
2475-1456
DOI
https://doi.org/10.1109/LCSYS.2018.2866234
Publication date
04-2019
Peer reviewed
Yes
Austrian Fields of Science 2012
208003 Environmental biotechnology
Keywords
ASJC Scopus subject areas
Control and Systems Engineering, Control and Optimization
Portal url
https://ucrisportal.univie.ac.at/en/publications/d53c74bb-a620-4fef-8976-c355e0542f7a