Figure 1.

Metabolic pathways for methane oxidation (A) and FA synthesis (B) in M. buryatense 5G(B1) based on a gene inventory study, transcriptomic data analysis, and genome-scale modeling (De la Torre et al., 2015). Numbers in blue represent that particular reaction's fluxes according to the developed genome-scale model (De la Torre et al., 2015); numbers in black after gene names denote abundances of respective transcript normalized to an abundance of methanol dehydrogenase. Gene names coding enzymes of the methane assimilation pathways are extracted from BioCyc Database Collection (http://biocyc.org/). Enzyme EC numbers and corresponding gene IDs are listed in Table S5. Methane utilization starts from oxidation to methanol by methane monooxygenase enzyme in periplasm; methanol is then metabolized to formaldehyde by a periplasmic pyrroloquinoline quinone-linked methanol dehydrogenase. Formaldehyde is either oxidized to CO₂ or assimilated in cytoplasm through ribulose monophosphate (RuMP) and EMP/EDD (Embden-Meyerhof-Parnas/Entner–Doudoroff) pathways (A), fraction of which are then converted through pyruvate to acetyl-CoA, a precursor for FA synthesis (B). Designations: CH₄, methane; CH₂0, formaldehyde; CHO₂, formate; H4MTP, tetrahydromethanopterin pathway; H4F, methylene tetrahydrofolate pathway; CO₂, carbon dioxide; f6p, fructose 6-phosphate; acCoA, acetyl-CoA; NADH, nicotinamide adenine dinucleotide reduced; NADPH, dihydronicotinamide adenine dinucleotide phosphate reduced; ATP, adenosine-triphosphate.