脉冲强光对大肠杆菌细胞膜损伤及胞内酶活性的影响

Damage of E.coli cell membrane and intracellular enzymic activity induced by pulsed light irradiation

通过脉冲强光处理对数生长期大肠杆菌细胞悬液,研究菌体细胞膜通透性及胞内酶活性的变化。结果表明,蛋白质的漏出量及丙二醛的生成量均随大肠杆菌存活率的下降而增加,在处理电压1500V、闪照次数32次的条件下,蛋白质漏出量为13.03μg/mL,丙二醛生成量为2.76nmol/L,对氯化钠的耐受性明显低于对照组(P<0.01)。此外,胞内酶活性与处理前相比均有所降低,超氧化物歧化酶活性最低降至83.78%,过氧化氢酶活性最低降至76.92%。因此,细菌屏障结构破坏所造成的细胞膜渗透压及通透性改变,可使细菌胞内物质发生改变,甚至导致菌体死亡,羟自由基可能对致死细胞的协同作用有一定的意义。

After pulsed light treatment on the suspension of E.coli in logarithmic growth phase,research the change of cell membrane permeability and intracellular enzymic activity.The result indicated that protein leakage and MDA formation increased with the decline of the survival rate of E.coli.Through pilot studies,drawn input voltage to 1 500 V,flash as 32times,the leakage of protein was 13.03μg/mL and the formation amount of MDA was 2.76nmol/L.NaCl tolerance was obviously lower than the control group（P 0.01）.In addition,intracellular enzymic activity lower than untreated,SOD was decreased to 83.78%as well as CAT was decreased to 76.92%.Therefore,the damage of cell barrier structure caused the change of osmotic pressure and cell membranes permeability.It can change intracellular bacterial substances even it caused cell died.It would be certain meaning that synergistic reaction which hydroxyl radicals acted on lethality cell.