Flexible nitrogen utilisation by the metabolic generalist pathogen Mycobacterium tuberculosis
Abstract
Bacterial metabolism is fundamental to survival and pathogenesis. We explore how Mycobacterium tuberculosis utilises amino acids as nitrogen sources, using a combination of bacterial physiology and stable isotope tracing coupled to mass spectrometry metabolomics methods. Our results define core properties of the nitrogen metabolic network from M. tuberculosis, such as: (i) the lack of homeostatic control of certain amino acid pool sizes; (ii) similar rates of utilisation of different amino acids as sole nitrogen sources; (iii) improved nitrogen utilisation from amino acids compared to ammonium; and (iv) co-metabolism of nitrogen sources. Finally, we discover that alanine dehydrogenase, is involved in ammonium assimilation in M. tuberculosis, in addition to its essential role in alanine utilisation as a nitrogen source. This study represents the first in-depth analysis of nitrogen source utilisation by M. tuberculosis and reveals a flexible metabolic network with characteristics that are likely product of evolution in the human host.
Data availability
Metabolomics data used on this study are available via Zenodo (DOI 10.5281/zenodo.2551162).
Article and author information
Author details
Funding
Wellcome (104785/B/14/Z)
- Aleksandra Agapova
- Agnese Serafini
- Michael Petridis
- Luiz Pedro Sorio de Carvalho
Wellcome (Francis Crick Institute Core funding (10060))
- Debbie M Hunt
- Acely Garza-Garcia
- Luiz Pedro Sorio de Carvalho
Medical Research Council (Francis Crick Institute Core funding (10060))
- Debbie M Hunt
- Acely Garza-Garcia
- Luiz Pedro Sorio de Carvalho
Cancer Research UK (Francis Crick Institute Core funding (10060))
- Debbie M Hunt
- Acely Garza-Garcia
- Luiz Pedro Sorio de Carvalho
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Reviewing Editor
- Bavesh D Kana, University of the Witwatersrand, South Africa
Version history
- Received: August 15, 2018
- Accepted: January 22, 2019
- Accepted Manuscript published: January 31, 2019 (version 1)
- Version of Record published: February 4, 2019 (version 2)
Copyright
© 2019, Agapova et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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