TABLE 1.
Key cytochromes in extracellular electron transfer in G. sulfurreducens
| Name | Location | Reduction potentialb |
Substrateb |
||
|---|---|---|---|---|---|
| MP | W | In vitro | In vivo | ||
| Cbca | Inner membrane | ND | ND | ND | An, FC, FO |
| ImcH | Inner membrane | ND | ND | ND | An, FC, FE, Mn |
| PpcAc | Periplasm | −167 | 210 | Aq, FC, FO, FN, H, Mn, U, Cr, S | Aq, FC, U |
| OmcB | Outer membrane, porin complex | −190 | ND | FC, FN, FO | FC, FO |
| OmcS | Outer membrane, e-pili | −212 | 320 | Aq, Au, Cr, FC, FO, H, Mn, U | An, D, Fe(0), FO, Mn |
| OmcZ | Anode-biofilm interface | −220 | 360 | Aq, Au, Cr, FC, U, Mn | An, Fe(0), U |
a
Cbc includes Cbc1, Cbc3, and Cbc5 complexes.
b
ND, not determined; MP, midpoint reduction potential (mV); W, reduction potential window (mV); In vitro, reduction by purified cytochrome; In vivo, negative impact on growth by gene deletion; An, anode; Aq, AQDS; Au, Au(III); Cr, Cr(VI); D, DIET; FC, Fe(III) citrate; FE, Fe(III)-EDTA; FN, Fe(III)-nitrilotriacetic acid; FO, Fe(III) oxide; H, humic acid; Mn, Mn(IV) oxide; S, elemental sulfur; U, U(VI).
c
Reduction potentials for PpcA are from reference 52.