TABLE 3.
Oxidation potential and inhibitory effect of iron-chelator complexes
| Complex | Eo (V)a | Effect on enzymatic cellulolysisc |
|---|---|---|
| Fe(III)(2,2′BP)2Cl3 | 0.78 | ∼100% loss in initial rate, ∼100% loss in extended hydrolysis extent |
| Fe(II)(2,2′BP)2Cl2 | ∼40% loss in initial rate, ∼40% loss in extended hydrolysis extent | |
| K3Fe(III)(CN)6 | 0.358 | No significant change in initial rate, no change in extended hydrolysis extent |
| K4Fe(III)(CN)6 | ∼10% loss in initial rate, ∼20% loss in extended hydrolysis extent | |
| Fe(III)NaEDTA | 0.13b | ∼10% loss in initial rate, ∼20% loss in extended hydrolysis extent |
| Fe(II)Na2EDTA | ∼80% loss in initial rate, ∼80% loss in extended hydrolysis extent | |
| Fe(III)-citrate | −0.191b | No significant change in initial rate, no change in extended hydrolysis extent |
a
Single-electron oxidation potential (19).
b
Data from references 3 and 6. Iron-chelator complexes without Eo entry are reduced counterparts of the corresponding oxidized complexes (Eo given).
c
Hydrolysis of 23 g/liter Avicel by 0.25 g/liter cellulase mix in 50 mM Na-acetate at pH 5 and at 50°C for 4 days.