AUTHOR=Saldivar Alexis , Ruiz-Ruiz Patricia , Revah Sergio , Zuñiga Cristal 

TITLE=Genome-scale flux balance analysis reveals redox trade-offs in the metabolism of the thermoacidophile Methylacidiphilum fumariolicum under auto-, hetero-and methanotrophic conditions

JOURNAL=Frontiers in Systems Biology

VOLUME=4

YEAR=2024

URL=https://www.frontiersin.org/journals/systems-biology/articles/10.3389/fsysb.2024.1291612

DOI=10.3389/fsysb.2024.1291612

ISSN=2674-0702

ABSTRACT=<p>Members of the genus <italic>Methylacidiphilum</italic> are thermoacidophile methanotrophs with optimal growth temperatures between 50°C and 60°C, and pH between 1.0 and 3.0. These microorganisms, as well as other extremophile bacteria, offer an attractive platform for environmental and industrial biotechnology because of their robust operating conditions and capacity to grow using low-cost substrates. In this study, we isolated <italic>Methylacidiphilum fumariolicum</italic> str. Pic from a crater lake located in the state of Chiapas, Mexico. We sequenced the genome and built a genome-scale metabolic model. The manually curated model contains 667 metabolites, 729 reactions, and 473 genes. Predicted flux distributions using flux balance analysis identified changes in redox trade-offs under methanotrophic and autotrophic conditions (H<sub>2</sub>+CO<sub>2</sub>). This was also predicted under heterotrophic conditions (acetone, isopropanol, and propane). Model validation was performed by testing the capacity of the strains to grow using four substrates: CH<sub>4</sub>, acetone, isopropanol, and LP-Gas. The results suggest that the metabolism of <italic>M. fumariolicum</italic> str. Pic is limited by the regeneration of redox equivalents such as NAD(P)H and reduced cytochromes.</p>