用NBT还原法检测细菌无细胞溶解物中SOD活性

目的：了解不同细菌无细胞溶解物中ＳＯＤ活性。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。结果：２株大肠杆菌ＳＯＤ活性明显低于８株沙门氏菌（Ｐ＜０．０１）；鼠伤寒沙门氏菌ＳＯＤ活性明显高于伤寒沙门氏菌（Ｐ＜０．０１）；而伤寒沙门氏菌Ｌ型返祖株ＳＯＤ活性低于其它株伤寒沙门氏菌（Ｐ＜０．０１）。结论：不同细菌的ＳＯＤ活性有差异；伤寒沙门氏菌Ｌ型返祖株细胞壁的缺陷可能是导致其ＳＯＤ活性降低的原因之一

Detection of SOD activity in cell free extracts from bacteria with NBT reduction assay

Objective:To detect the superoxide dismutase(SOD)activity in cell free extracts from different bacteria. Methods: 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.Results:The SOD activity of two strains of E.coli was obviously lower than that of eight strains of Salmonella (P< 0.01),and the SOD activity of E.coli and S.typhi was lower than that of a strain of S.typhimurium(P<0.01),but in the cell free extracts from a strain of S.typhi L type reverstant(Str),the SOD activity was lower than that of the other strains of S.typhi(P <0.01).Conclusion:The SOD activity in cell free extracts from different bacteria vary from each other,and in S,typhi,the deficiency of the cell wall may result in the descent of SOD activity.