摘要
为了阐明大肠杆菌(E.coli)抗氧化基因(ahp C/F、kat E/G、oxyR ahp C/F、sod A/B)对细菌内源过氧化氢(H2O2)调控中的协同作用,本研究以E.coli抗氧化基因突变株及其野生型菌株为研究对象,通过紫外分光光度法分析过氧化氢酶活性变化,荧光法检测内源H2O2浓度变化,组织化学法对细胞内H2O2进行定量和定位分析,光密度法分析菌株生长规律。结果表明,与野生型菌株相比,突变体JI367、JI370和AS240生长过程中过氧化氢酶活性总体升高,整个生长周期内H2O2浓度降低,而LC74过氧化氢酶活性降低,整个生长周期中内源H2O2浓度升高;组织化学染色法表明各菌株内源H2O2有显著差异(p<0.05),LC74内源H2O2累积量最多;JI367、JI370和AS240生长迟缓,LC74对数期后期生长速度较野生型快。结果说明,当H2O2浓度累积到高于大约5.4μmol/L时促进E.coli生长,不同的抗氧化基因之间受调控子蛋白OxyR调控存在补偿性表达作用,抗氧化酶Ahp C/F在降解内源H2O2方面起主要作用。本实验为细菌内源H2O2的调控机制的系统研究提供了新的证据。
To elucidate the synergy of anti-oxidative gene（ ahpC/F, katE/G, oxyR ahpC/F, sodA/B）on endogenous hydrogen peroxide（ H2O2 ）regulation in Escherichia coil（E.cofi）. In this study, E. coil antioxidant gene mutants and wild type strain were used as the research object, ultraviolet spectrophotography was applicable for the assay of the hydrogen peroxide enzyme activity, fluorescence method was used to detect the endogenous H2O2 concentration,the quantity and localization of endogenous H2O2were obtained by histochemical method, growth rule of the strains was determined by optical density. Results showed that compared with wild type strains, the hydrogen peroxide enzyme activity was overall elevated in the process of growth in mutant strains JI367, JI370 and AS240,H2O2 concentration in the whole growth cycle was reduced, but the results of the mutant strain LC74 was opposite.The results of histochemical staining showed that the accumulation of intracellular H2O2in cell wall existed differences（p 〈 0.05）, mutant strain LC74 had the most endogenous H202 cumulant, mutant strains JI367,JI370 and AS240 grew slowly,the growth speed of the mutant strain LC74 was faster than wild type in late logarithmic. Results showed that when the concentration of H202 accumulated to about more than 5.4pmol/L which would promote growth,the different antioxidant genes was regu action,antioxidant enzymes AhpC/F prayed a main role fn evidence to bacteria regulatory mechanism of endogenous ated by OxyR and existed compensatory expression the endogenous H2O2.This experiment provide a new H2 O2.
出处
《食品工业科技》
CAS
CSCD
北大核心
2014年第21期167-171,共5页
Science and Technology of Food Industry
基金
国家自然科学基金(31000017
31200035)
关键词
H2O2
抗氧化基因
E.COLI
生长曲线
酶活
endogenous hydrogen peroxide
anti-oxidative gene
Escherichia coli
growth curve
enzymic activity
