The SOD activity in cell free extracts from two strains of Escherichia coli and eight strains of Salmonella (including seven strains of S. typhi and a strain of S.typhimurium)was detected by the inhibition of nitro tetrazolium(NBT)reduction.

• 方法：采用NBT还原法检测2株大肠杆菌和8株沙门氏菌（其中7株伤寒沙门氏菌、1株鼠伤寒沙门氏菌）无细胞溶解物中SOD活性。