TABLE 1.

Comparative energetic analysis of chlororespiration and Fe(III) reduction in A. dehalogenans and relevant respiration processes in other anaerobic bacteria

Process	Organism	Electron donor	Electron acceptora	Electron donor threshold (nM)	Residual ΔG (kJ/mol of electrons)	Reference(s) or source
Chlororespiration	Anaeromyxobacter dehalogenans	Acetate	2-CP	69 ± 4	−75.4	This study
Fe(III) reduction	Anaeromyxobacter dehalogenans	Acetate	Amorphous Fe(III)	19 ± 8	−41.5b	This study
Chlororespiration	Anaeromyxobacter dehalogenans	H2	2-CP	<0.01	−58.7c,d	12
Chlororespiration	Desulfitobacterium chlororespirans	H2	3Cl-4-HBA	0.27	−62.0c	12, 21
Chlororespiration	Desulfitobacterium sp. strain Viet1	H2	PCE	0.4	−72.1c	12
Chlororespiration	Mixed culture	H2	DCE	2	−57.8	27
Methanogenesis	Methanothrix soehngenii	Acetate	Acetate	7,000-69,000	−3.5c	9
Methanogenesis	Mixed culture	H2	CO2	11	−5.8	27
Acetogenesis	Acetobacterium woodii	H2	CO2	510	−6.8	19, 27

^a3Cl-4-HBA, 3-chloro-4-hydroxybenzoate; PCE, perchloroethene; DCE, cis-1,2-dichloroethens.

^bThe change in Gibbs free energy in the reduction of amorphous Fe(III) oxyhydroxide was computed with reduction potential data from reference 20.

^cCalculations of ΔG were based on the following concentrations: acetate and H₂, threshold concentrations; chloroethenes, 5 ppm by volume; aromatic species, 1 mM; CH₄, 1,000 ppm by volume; Cl⁻, 1 mM; HCO₃⁻, 30 mM; and pH 7.

^dCalculated based on a H₂ threshold of 0.01 nM.