Fig. 3
From: Anaerobic microsites have an unaccounted role in soil carbon stabilization
Bioenergetic projections for the mineralization of organic compounds under aerobic and anaerobic conditions. The thermodynamic driving force, F T, is given for the oxidation of organic compounds spanning a range of nominal oxidation states when coupled to the reduction of oxygen (aerobic respiration) or Fe(OH)3 (anaerobic respiration). When coupled to oxygen (gray line), F T for the oxidation of an organic compound is close to 1. Mineralization (R min) is thus expected to proceed uninhibited for compounds spanning the full range of oxidation states. Under Fe(OH)3-reducing conditions (orange line), mineralization of more oxidized compounds, such as sugars, yields projected rates comparable to those under aerobic conditions (60–80%). By contrast, mineralization of reduced organic compounds, such as lipids, would proceed at limited rates or may even be completely inhibited (0–30%), resulting in a relative enrichment, and ultimately preservation, of these abundant compound classes in anaerobic microsites
