Open AccessA genuine mycobacterial thermophile: Mycobacterium hassiacum growth, survival and GpgS stability at near-pasteurization temperatures
Author(s) -
Susana Alarico,
Daniela Nunes-Costa,
Alexandra Silva,
Mafalda Costa,
Sandra Macedo-Ribeiro,
Nuno Empadinhas
Publication year - 2020
Publication title -
microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.352
H-Index - 35
eISSN - 1465-2080
pISSN - 1350-0872
DOI - 10.1099/mic.0.000898
Subject(s) - mycobacterium , biology , nontuberculous mycobacteria , microbiology and biotechnology , mycobacterium tuberculosis , mycobacterium fortuitum , mycobacterium chelonae , thermophile , pasteurization , glycerol , tuberculosis , bacteria , food science , biochemistry , genetics , medicine , pathology
Mycobacterium hassiacum is so far the most thermophilic among mycobacteria as it grows optimally at 50 °C and up to 65 °C in a glycerol-based medium, as verified in this study. Since this and other nontuberculous mycobacteria (NTM) thrive in diverse natural and artificial environments, from where they may access and infect humans, we deemed essential to probe M. hassiacum resistance to heat, a strategy routinely used to control microbial growth in water-supply systems, as well as in the food and drink industries. In addition to possibly being a threat in its own right in rare occasions, M. hassiacum is also a good surrogate for studying other NTM species more often associated with opportunistic infection, namely Mycobacterium avium and Mycobacterium abscessus as well as their strictly pathogenic counterparts Mycobacterium tuberculosis and Mycobacterium leprae . In this regard, this thermophilic species is likely to be useful as a source of stable proteins that may provide more detailed structures of potential drug targets. Here, we investigate M. hassiacum growth at near-pasteurization temperatures and at different pHs and also characterize its thermostable glucosyl-3-phosphoglycerate synthase (GpgS), an enzyme considered essential for M. tuberculosis growth and associated with both nitrogen starvation and thermal stress in different NTM species.