大肠杆菌抗氧化系统-oxyR调节子对细菌生长繁殖的调控作用  

Effects of oxyR Regulon, the Bacterial Antioxidant Defense on Escherichia coli's Growth and Reproduction

作　　者：李欣[1] 王利平[1] 杜琳[1] 杨丽鹏[1] 乔家驹 李红玉[2] 冯汉青[3] 

机构地区：[1]河南科技大学食品与生物工程学院,中国河南洛阳471023 [2]兰州大学生命科学学院,中国甘肃兰州730000 [3]西北师范大学生命科学学院,中国甘肃兰州730070

出　　处：《生命科学研究》2014年第4期323-326,343,共5页Life Science Research

基　　金：国家自然科学基金资助项目(31000017;31260059;31071335)

摘　　要：oxyR调节子是最早发现的细菌抗氧化防御系统之一,大肠杆菌oxyR调节子中参与抗氧化作用的基因成员包括katG、ahpC、ahpF等,通过对H2O2及过氧化物等的直接清除方式发挥作用。虽然该方面的研究很多,但对于大肠杆菌oxyR调节子对细菌生长繁殖的影响尚不清楚。通过对大肠杆菌oxyR、ahpCF、katE/G基因突变菌株进行研究,突变体JI370中ahpCF基因缺失导致其内源H2O2积累减少使其生长相应加快,而对于katG和katE基因突变体JI367和ahpCF、oxyR基因突变体LC74来说,胞内H2O2极显著上升会抑制细菌生长,并且H2O2积累量越大对其生长抑制作用越明显。与野生型菌株相比,ahpCF的缺失突变菌株JI370和ahpCF及oxyR双突变的LC74在菌株生长的潜伏期受到更显著的影响。结果表明:在CAT(catalase,CAT)与AHP(alkyl hydroperoxide reductase,AHP)协同清除内源H2O2的作用中,AHP起到主导作用,并且在细菌的生长繁殖中,ahp基因起到重要的作用。oxyR regulon was one of the earliest bacterial antioxidant defense system found by researchers. In Escherichia coli, oxyR regulon, including katG, ahpC, ahpF, was employed to cope with antioxidant response by directly scavenging H2O2, peroxide and so on. Although lots of research on the antioxidant have been reported, its effect on bacterial growth and reproduction is still not clear. The results of oxyR, ahpCF, katE/G gene mutant strains of E. coli showed that, due to the lock of ahpCF genes in mutant JI370, its endogenous H2O2 were reduced. The growth of JI370 was promoted. On the contrast, as for the mutant strains JI367 and LC74, the accumulation of endogenous H2O2 were significantly increased; their growth were inhibited. The accumulation of H2O2 was higher with the stronger inhibition. Compared with wild type strains, mutant strain JI370 and LC74 were affected more significantly in the early stage of growth. The results showed that in the endogenous H2O2 scavenging activities of CAT and AHP, AHP played a dominant role. And in the bacterial growth and reproduction, gene ahp was more important than kat.

关 键 词：过氧化氢酶 过氧化氢 大肠杆菌 生长繁殖 

分 类 号：Q935[生物学—微生物学]