Fig. 4
From: Assessing methanotrophy and carbon fixation for biofuel production by Methanosarcina acetivorans
Biofuel yields using methane (shaded in black) as the sole carbon source and HCO3 −/CH4 (shaded in gray) with a ratio of 0.44 for ferric-dependent (a) and sulfate-dependent (b) methanotrophy. The dashed bars denote the excess carbons that could not be incorporated into the product due to thermodynamic restrictions. Ferric-dependent methanotrophy predicted increased yields at higher HCO3 −/CH4 ratios, but the carbon conversion was less than 100 %. Sulfate-dependent methanotrophy cannot achieve 100 % carbon conversion at any HCO3 −/CH4 ratio due to mandatory co-production of thermodynamically feasible by-products. Product yields are in mol per mol methane