Methane utilization in Methylomicrobium alcaliphilum 20ZR: a systems approach

Sci Rep. 2018 Feb 6;8(1):2512. doi: 10.1038/s41598-018-20574-z.

Abstract

Biological methane utilization, one of the main sinks of the greenhouse gas in nature, represents an attractive platform for production of fuels and value-added chemicals. Despite the progress made in our understanding of the individual parts of methane utilization, our knowledge of how the whole-cell metabolic network is organized and coordinated is limited. Attractive growth and methane-conversion rates, a complete and expert-annotated genome sequence, as well as large enzymatic, 13C-labeling, and transcriptomic datasets make Methylomicrobium alcaliphilum 20ZR an exceptional model system for investigating methane utilization networks. Here we present a comprehensive metabolic framework of methane and methanol utilization in M. alcaliphilum 20ZR. A set of novel metabolic reactions governing carbon distribution across central pathways in methanotrophic bacteria was predicted by in-silico simulations and confirmed by global non-targeted metabolomics and enzymatic evidences. Our data highlight the importance of substitution of ATP-linked steps with PPi-dependent reactions and support the presence of a carbon shunt from acetyl-CoA to the pentose-phosphate pathway and highly branched TCA cycle. The diverged TCA reactions promote balance between anabolic reactions and redox demands. The computational framework of C1-metabolism in methanotrophic bacteria can represent an efficient tool for metabolic engineering or ecosystem modeling.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Acetyl Coenzyme A / metabolism
  • Citric Acid Cycle
  • Computer Simulation
  • Metabolic Networks and Pathways
  • Metabolome
  • Methane / metabolism*
  • Methanol / metabolism*
  • Methylococcaceae / enzymology
  • Methylococcaceae / growth & development
  • Methylococcaceae / metabolism*
  • Pentose Phosphate Pathway

Substances

  • Acetyl Coenzyme A
  • Methane
  • Methanol