纳米二氧化硅自由基对人体常驻大肠杆菌的界膜氧化作用

发布时间：2018-06-03 02:15

本文选题：纳米二氧化硅 + 大肠杆菌　；参考：《环境与健康杂志》2015年05期

【摘要】：目的探讨纳米二氧化硅对大肠杆菌的界膜氧化作用及机制。方法将大肠杆菌悬液分别加入至含终浓度为0(对照)~4 000μg/ml纳米二氧化硅的PBS缓冲液中培养24 h。通过对纳米二氧化硅溶液中羟基自由基、细胞存活率的测定,并结合细胞壁表面基团、胞内活性氧自由基、超氧化物歧化酶(SOD)和乳酸脱氢酶(LDH)活力的变化,分析纳米二氧化硅对大肠杆菌的界膜氧化作用机制。结果与对照组比较,1 000、2 000、4 000μg/ml纳米二氧化硅暴露组大肠杆菌的存活率均较低,大肠杆菌胞内ROS的含量均较高;各浓度纳米二氧化硅暴露组在PBS缓冲液中释放羟基自由基的含量均上升,大肠杆菌释放LDH的量均较高;4 000μg/ml纳米二氧化硅暴露组大肠杆菌胞内SOD活力较低,差异有统计学意义(P0.05)。且随着纳米二氧化硅浓度的升高,体系中羟基自由基和ROS的含量及大肠杆菌释放LDH的量均呈上升趋势,大肠杆菌的存活率和SOD活力均呈下降趋势。细胞壁表面磷酸二酯基团峰(1 078 cm-1与1 239 cm-1)消失,蛋白质分子中甲基对称(1 400 cm-1)弯曲振动峰发生红移。结论纳米二氧化硅对大肠杆菌的界膜氧化作用主要体现于自由基对细胞壁膜的损伤以及抗氧化体系的破坏。
[Abstract]:Objective to investigate the effect and mechanism of nano silica on the oxidation of the membrane of Escherichia coli. Methods the culture of Escherichia coli suspension was added to the PBS buffer solution of 0 (control) ~4 000 g/ml nanoscale silica, respectively, to determine the survival rate of the hydroxyl radicals in the nano silica solution and the cell wall table. The changes in the activity of surface groups, intracellular reactive oxygen radicals, superoxide dismutase (SOD) and lactate dehydrogenase (LDH), and analysis of the oxidation mechanism of nano silica to the membrane of Escherichia coli. Compared with the control group, the survival rate of Escherichia coli in 1 000,2 000,4 000 g/ml nanoscale silica exposed group was lower, and the intracellular ROS in Escherichia coli The content of the release of hydroxyl radicals in the PBS buffer solution increased and the amount of LDH released by Escherichia coli was higher, and the intracellular SOD activity of Escherichia coli in the 4000 u g/ml nanoscale exposed group was lower, and the difference was statistically significant (P0.05). The content of hydroxyl radical and ROS in the system and the amount of LDH released by Escherichia coli were all rising, the survival rate and SOD activity of Escherichia coli decreased. The peak of phosphoric acid two ester group (1078 cm-1 and 1239 cm-1) on the surface of cell wall disappeared, and the peak of methyl symmetric (1400 cm-1) in the protein molecule was red shift. Conclusion the nano two oxygen is two oxygen. The oxidation of silicon on Escherichia coli is mainly due to the damage of free radicals to cell membrane and the destruction of antioxidant system.
【作者单位】：西南科技大学固体废物处理与资源化教育部重点实验室;西南科技大学材料科学与工程学院;绵阳404医院检验科;西南科技大学生命科学与工程学院;
【基金】：国家自然科学基金(41130746;41102213) 国家重点基础研究发展计划(973)项目(2014CB846003)
【分类号】：R114

【参考文献】