Fundamental Bioengineering

5A Primer to ¹³C Metabolic Flux Analysis

Wolfgang Wiechert,Sebastian Niedenführ and Katharina Nöh

Summary

The experimental determination of metabolic reaction rates (fluxes) in a physiological steady state of a cell is called metabolic flux analysis (MFA) or, sometimes, “quantitative fluxomics”. In the concert of the “omics” techniques, fluxomics plays a distinguished role because it characterizes the quantitative phenotype that emerges from regulation on all levels of cellular organization. Whereas the genome, proteome, or metabolome give the cells' inventory and reveal what a cell population can potentially achieve, a metabolic flux map describes the actual cellular function.

Instead of direct observation, MFA is based on a computational procedure in which intracellular fluxes in a given network model are calculated from measured uptake and production rates of extracellular substrates and products. This chapter provides an introduction to the principles of the currently most advanced MFA technique based on isotopic tracers ($\mathrm{C}_{13}$ MFA). It concentrates on modeling and data analysis by using a simple but highly instructive example network. With this example at hand, all steps of a typical $\mathrm{C}_{13}$-MFA evaluation workflow are discussed. A nontechnical overview of good practices as a guideline for choosing an appropriate software system finalizes the chapter.

5.1 Introduction

The experimental determination of metabolic fluxes in a physiological steady state of a cell is called metabolic ...