Advances in analysis of microbial metabolic fluxes via ¹³C isotopic labeling

Abstract Metabolic flux analysis via 13 C labeling ( 13 C MFA) quantitatively tracks metabolic pathway activity and determines overall enzymatic function in cells. Three core techniques are necessary for 13 C MFA: (1) a steady state cell culture in a defined medium with labeled‐carbon substrates; (2) precise measurements of the labeling pattern of targeted metabolites; and (3) evaluation of the data sets obtained from mass spectrometry measurements with a computer model to calculate the metabolic fluxes. In this review, we summarize recent advances in the 13 C‐flux analysis technologies, including mini‐bioreactor usage for tracer experiments, isotopomer analysis of metabolites via high resolution mass spectrometry (such as GC‐MS, LC‐MS, or FT‐ICR), high performance and large‐scale isotopomer modeling programs for flux analysis, and the integration of fluxomics with other functional genomics studies. It will be shown that there is a significant value for 13 C‐based metabolic flux analysis in many biological research fields. © 2009 Wiley Periodicals, Inc., Mass Spec Rev 28:362–375, 2009