Archaea

Research Article

Archaea and Bacteria Acclimate to High Total Ammonia in a Methanogenic Reactor Treating Swine Waste

Table 1

Stoichiometry and thermodynamics of syntrophic acetate, propionate, and butyrate fermentation.


Acetate fermentation	(1a) CH₃COO⁻ + H⁺ + 2H₂O 2CO₂ + 4H₂	= +55.0
Propionate fermentation	(1b) C₃H₅OO⁻ + 2H₂O CH₃COO⁻ + CO₂ + 3H₂	= +76.0
Butyrate fermentation	(1c) C₄H₇OO⁻ + 2H₂O 2CH₃COO⁻ + H⁺ + 2H₂	= +48.3
Hydrogen oxidation	(2) 4H₂ + CO₂ CH₄ + 2H₂O	= −130.8
(1a) + (2)	(3) CH₃COO⁻ + H⁺ CO₂ + CH₄	= −75.8
(1b) + (2)	(4) C₃H₅OO⁻ + H₂O CH₃OO⁻ + CH₄ + CO₂	= −28.0
(1c) + (2)	(5) C₄H₇OO⁻ + 2H₂ + CO₂ 2CH₃COO⁻ + H⁺ + CH₄	= −42.6

The standard free enthalpies of formation () are reported in kJ reaction⁻¹ at 1 M, pH 7, and 25°C.