Assessing methanotrophy and carbon fixation for biofuel production by Methanosarcina acetivorans. Issue 1 (December 2016)

• Record Type: Journal Article
• Authors: Nazem-Bokaee, Hadi; Gopalakrishnan, Saratram; Ferry, James; Wood, Thomas; Maranas, Costas
• Is Part Of: Microbial cell factories. Volume 15:Issue 1(2016)
• Page Start: 1
• Page End: 13
• Publication Date: 2016-12
• Subjects: Methanosarcina acetivorans -- Genome-scale metabolic model -- Methane utilization; Microbial biotechnology -- Periodicals; Recombinant proteins -- Synthesis -- Periodicals; 660.62
• DOI: 10.1186/s12934-015-0404-4
• Languages: English
• ISSNs: 1475-2859

Abstract

Abstract Background Methanosarcina acetivorans is a model archaeon with renewed interest due to its unique reversible methane production pathways. However, the mechanism and relevant pathways implicated in (co)utilizing novel carbon substrates in this organism are still not fully understood. This paper provides a comprehensive inventory of thermodynamically feasible routes for anaerobic methane oxidation, co-reactant utilization, and maximum carbon yields of major biofuel candidates byM. acetivorans . Results Here, an updated genome-scale metabolic model ofM. acetivorans is introduced (iMAC868 containing 868 genes, 845 reactions, and 718 metabolites) by integrating information from two previously reconstructed metabolic models (i.e., iVS941 and iMB745), modifying 17 reactions, adding 24 new reactions, and revising 64 gene-protein-reaction associations based on newly available information. The new model establishes improved predictions of growth yields on native substrates and is capable of correctly predicting the knockout outcomes for 27 out of 28 gene deletion mutants. By tracing a bifurcated electron flow mechanism, the iMAC868 model predicts thermodynamically feasible (co)utilization pathway of methane and bicarbonate using various terminal electron acceptors through the reversal of the aceticlastic pathway. Conclusions This effort paves the way in informing the search for thermodynamically feasible ways of (co)utilizing novel carbon substrates in the domainArchaea .