Metabolomics of central carbon metabolism in Mycobacterium tuberculosis

Metabolism is a biochemical activity of all cells, thought to fuel the physiologic needs of a given cell in a quantitative, rather than qualitatively specific, manner. Mycobacterium tuberculosis is a chronic facultative intracellular pathogen that resides in humans as its only known host and reservoir. Within humans, M. tuberculosis resides chiefly in the macrophage phagosome, the cell type and compartment most committed to its eradication. M. tuberculosis thus occupies the majority of its decades-long life cycle in a state of slowed or arrested replication. At the same time, M. tuberculosis remains poised to reenter the cell cycle to ensure its propagation as a species. M. tuberculosis has thus evolved its metabolic network to both maintain and propagate its survival as a species within a single host. Knowledge of the specific ways in which its metabolic network serves these distinct though interdependent functions, however, remains highly incomplete. In this article we review existing knowledge of M. tuberculosis's central carbon metabolism as reported by studies of its basic genetic and biochemical composition, regulation, and organization, with the hope that such knowledge will inform our understanding of M. tuberculosis's ability to traverse the stringent and heterogeneous niches encountered in the host.