Metabolic fluxes for nutritional flexibility of Mycobacterium tuberculosis

Khushboo Borah, Tom A. Mendum, Nathaniel D. Hawkins, Jane L. Ward, Michael H. Beale, Gerald Larrouy-Maumus, Apoorva Bhatt, Martine Moulin, Michael Haertlein, Gernot Strohmeier, Harald Pichler, V. Trevor Forsyth, Stephan Noack, Celia W. Goulding, Johnjoe McFadden, Dany J.V. Beste*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


The co-catabolism of multiple host-derived carbon substrates is required by Mycobacterium tuberculosis (Mtb) to successfully sustain a tuberculosis infection. However, the metabolic plasticity of this pathogen and the complexity of the metabolic networks present a major obstacle in identifying those nodes most amenable to therapeutic interventions. It is therefore critical that we define the metabolic phenotypes of Mtb in different conditions. We applied metabolic flux analysis using stable isotopes and lipid fingerprinting to investigate the metabolic network of Mtb growing slowly in our steady-state chemostat system. We demonstrate that Mtb efficiently co-metabolises either cholesterol or glycerol, in combination with two-carbon generating substrates without any compartmentalisation of metabolism. We discovered that partitioning of flux between the TCA cycle and the glyoxylate shunt combined with a reversible methyl citrate cycle is the critical metabolic nodes which underlie the nutritional flexibility of Mtb. These findings provide novel insights into the metabolic architecture that affords adaptability of bacteria to divergent carbon substrates and expand our fundamental knowledge about the methyl citrate cycle and the glyoxylate shunt.

Original languageEnglish
Article numbere10280
JournalMolecular Systems Biology
Issue number5
Publication statusPublished - May 2021


  • chemostat
  • metabolic flux
  • metabolism
  • Mycobacterium tuberculosis
  • tuberculosis

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)
  • Immunology and Microbiology(all)
  • Agricultural and Biological Sciences(all)
  • Applied Mathematics

Fields of Expertise

  • Human- & Biotechnology


  • NAWI Graz

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