. 2015 Jan 28;79(1):61–80. doi: 10.1128/MMBR.00037-14

TABLE 1.

Important inorganic forms of selenium, with oxidation states and redox potentials, along with other terminal electron acceptors of anaerobic respiration

Redox couple	Oxidation state	Half-reaction	E₀′ (V)^a
O₂/H₂O	0/−2	O₂ + 4e⁻ + 4H⁺ → 2H₂O	+0.81
NO₃⁻/N₂	+5/0	2NO₃⁻ + 10e⁻ + 12H⁺ → N₂ + 6H₂O	+0.75
MnO₂/Mn²⁺	+4/+2	MnO₂ + 2e⁻ + 4H⁺ → Mn²⁺ + 2H₂O	+0.53
SeO₄²⁻/SeO₃²⁻	+6/+4	SeO₄²⁻ + 2e⁻ + 2H⁺ → SeO₃²⁻ + H₂O	+0.48
NO₃⁻/NH₄⁺	+5/−3	NO₃⁻ + 8e⁻ + 10H⁺ → NH₄⁺ + 3H₂O	+0.36
SeO₃²⁻/Se⁰	+4/0	SeO₃²⁻ + 4e⁻ + 6H⁺ → S⁰ + 3H₂O	+0.21
Fe³⁺/Fe²⁺	+3/+2	Fe(OH)₃ + 1e⁻ + 3H⁺ → Fe²⁺ + 3H₂O	+0.10
SO₄²⁻/SO₃²⁻	+6/+4	SO₄²⁻ + 2e⁻ + 2H⁺ → SO₃²⁻ + H₂O	−0.516
Se⁰/HSe⁻	0/−2	Se⁰ + 2e⁻ + H⁺ → HSe⁻	−0.73

The theoretical reduction oxidation potentials (E₀′) under standard conditions were taken from references 1, 36, 146, 147, and 148.