Genome-Scale Modeling of Methane-Producing Microbes
Methane-producing microbes (i.e., methanogens) play a key role in the global carbon cycle and could significantly contribute to climate change due to the potent greenhouse gas properties of methane. These organisms occupy a central place in the biogeochemistry of soils, wetlands, and permafrost. However, it remains difficult to predict how they may respond to changing environmental conditions due to limited understanding of their biology. In a new study by DOE investigators at the University of Illinois, the first fully curated genome-scale metabolic model has been assembled for the methanogen Methanosarcina acetivorans. M. acetivorans is unique among methanogens in its ability to convert organic compounds such as acetate to methane, but it cannot perform the more traditional conversion of hydrogen and CO2. The new model’s predictions have been validated using flux balance analysis and gene knockouts. The model provides new information on the integration of central and peripheral metabolic pathways, an important step in developing a systems biology approach to understanding this methanogen’s behavior. These findings significantly increase our predictive understanding of this important class of microbes providing a powerful new tool to test hypotheses on their potential roles in climate change.
Benedict, M. N., M. C. Gonnerman, W. W. Metcalf, and N. D. Price. 2012. “Genome-Scale Metabolic Reconstruction and Hypothesis Testing in the Methanogenic Archaeon Methanosarcina acetivorans C2A,” Journal of Bacteriology 194, 855-65, DOI: 10.1128/JB.06040-11.