TABLE 2.

SodA-independent superoxide-scavenging activity in crude cell extract

Treatment	Total superoxide-scavenging activity (U/mg of protein)a
	168	BK1
None	10.0	6.7
EDTA, 1 mM	6.5	—c
100°C, 10 minb	5.5	5.7
Dialysis, 2 h	9.2	3.7
Dialysis, 12 h	9.2	<0.1

^aThe activity in the crude extract of each strain grown in MnCl₂-supplemented LB medium for 8 h was measured in non-EDTA-supplemented buffer as described in the text. Each protein concentration was determined before treatment. 

^bSamples were boiled for 10 min and then centrifuged. The activity in the supernatant was measured. 

^c—, activity below the limit of detection.