Title
Metabolic fluxes for nutritional flexibility of Mycobacterium tuberculosis
Author
Khushboo Borah, Tom A Mendium, 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 Beste
Year
2021
Journal
Molecuar Systems Biology
Abstract
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.
Instrument
LC-4000
Keywords
Mycobacterium tuberculosis, Mtb, TCA cycle, metabolic architecture