| Comments |
P.710 left column bottom paragraph: "In an early study on butanol fermentation mediated by Clostridium acetobutylicum, shuttles like neutral red (E'0 = −0.325 V versus a SHE [standard hydrogen electrode] Box 1) were thought to stimulate H2 uptake [ref 79], but it was later shown in vitro, using methyl viologen (E'0 = −0.460 V versus SHE Box 1) [ref 80], that electron shuttles can directly drive NAD(P)+ reduction to NAD(P)H using NAD(P)+ ferredoxin oxidoreductase [ref 64]. P.710 right column top paragraph: "Electron shuttles with higher midpoint potentials, such as anthraquinone-2,6-disulphonate (AQDS) (E'0 = −0.184 V versus SHE Box 1), were effective for the cathodic reduction of perchlorate [ref 66]. Again, the midpoint potential of AQDS indicates that EET [extracellular electron transfer] does not necessarily occur at the NADH/NAD+ (E'0 = −0.320 V versus SHE) level or even at the H2 (E'0 = −0.410 V versus SHE Box 1) level. The use of iron as an electron shuttle towards microorganisms in acidic conditions has also been investigated [ref 85]." See note above figure |