TABLE 1.
Summary reactions and thermodynamic parameters of mucin-derived sugar degradation by A. muciniphilaa
| Substrate | Degradation reaction | ΔrG′m (kJ/mol) | ΔrG′° (kJ/mol) |
|---|---|---|---|
| Glucose | Glucose (aq) ↔ 4/3 propionate (aq) + 2/3 acetate (aq) + 2/3 CO2 (aq) + 2/3 H2O (l) | −340.1 | −311.6 |
| Galactose | Galactose (aq) ↔ 4/3 propionate (aq) + 2/3 acetate (aq) + 2/3 CO2 (aq) + 2/3 H2O (l) | −347.1 | −318.5 |
| Fucose | Fucose (aq) + 1/3 H2O (l) ↔ 1,2-propanediol (aq) + 2/3 acetate (aq) + 1/3 propionate (aq) + 2/3 CO2 (aq) | −187.3 | −158.8 |
| GlcNAc | N-Acetyl-d-glucosamine (aq) + 4/3 H2O (l) ↔ 5/3 acetate (aq) + ammonia (aq) + 4/3 propionate (aq) + 2/3 CO2 (aq) | −375.6 | −312.9 |
| GalNAc | N-Acetyl-d-galactosamine (aq) + 4/3 H2O (l) ↔ 5/3 acetate (aq) + 3/3 ammonia (aq) + 4/3 propionate (aq) + 2/3 CO2 (aq) | −376.1 | −313.3 |
| NeuAc | N-Acetylneuraminate (aq) + 5/3 H2O (l) ↔ 5/3 propionate (aq) + 7/3 acetate (aq) + 4/3 CO2 (aq) + ammonia (aq) | −477.2 | −385.9 |
a
ΔrG′° is the standard reaction Gibbs energy (1 M). ΔrG′m is the reaction Gibbs energy with 1 mM standard, which is more suitable for comparing reactions in biological settings. The large negative numbers indicate thermodynamically favorable events and potentially more favorable kinetics for the amino-sugars. The summary pathways for the degradation of sugars were derived from the constructed metabolic model.