Identification of Multiple Soluble Fe(III) Reductases in Gram-Positive Thermophilic Bacterium Thermoanaerobacter indiensis BSB-33

Table 1

Localization of Fe(III) reductase activity.

Fraction	Total protein recovered; (mg)	Specific activity; (U/mg)	Total activity; (U)	% of activity in crude extract recovered
Crude extracts	880.5	0.052	45.8	100
Soluble fraction	609.8	0.057	34.8	76
Membrane fraction	95.9	0.02	1.9	4

One U (unit) is defined as the amount of enzyme reducing 1 µmol of Fe(III) per min.