Transcriptome of MTB H37Rv in glucose L-lactate and pyruvate

Mycobacterium tuberculosis has specialised its metabolism to reside extra- and intra-cellularly in the human host. Nutrient availability and their concentrations can vary dramatically in these niches. Lactate is abundant during infection and it is an important signalling molecule regulating the immune response. In addition, lactate is abundant in blood, epithelial mucosa and a number of  other relevant compartments in the host. Interestingly, previous studies have demonstrated that lactate and one of its possible first degradation products, pyruvate, allow superior growth compared to glucose and fatty acids in vitro for M. tuberculosis. Based on this information, we performed a "multi-omics" investigation to study the metabolism of pyruvate and lactate in M. tuberculosis. We employed TraDIS, transcriptomics, proteomics and stable isotopic labelling coupled with mass spectrometry-based metabolomics. Our studies reveal the structure of M. tuberculosis metabolic network associated with catabolism of pyruvate and lactate. Together these findings lead us to reconsider some well-accepted "truths" on carbon metabolism in M. tuberculosis. Overall design: Comparison of transcriptional profiles induced at 6h and 24h after shift to one carbon source selected between glucose, pyruvate and lactate in H37Rv