纳米TiO_2光催化杀灭大肠杆菌的超微结构研究  

Ultrastructural studies on the photocatalytical sterilization using titanium dioxide nanoparticles

作　　者：郭世宜[1] 沈星灿[2] 

机构地区：[1]南开大学生命科学学院,天津300071 [2]广西师范大学化学化工学院,广西桂林541004

出　　处：《电子显微学报》2004年第2期107-111,共5页Journal of Chinese Electron Microscopy Society

基　　金：广西壮族自治区自然科学基金资助项目[桂科青00339022].

摘　　要：在近紫外光的照射下,纳米TiO2具有较强的光催化灭菌效果。用透射电子显微镜较完整地研究纳米TiO2光催化杀灭大肠杆菌的超微结构变化。结果表明,纳米TiO2可直接或间接作用于大肠杆菌;光催化过程中产生的氢氧自由基等活性氧类物质可导致大肠杆菌的外壁和质膜严重破损、断裂;胞浆流出;细胞质凝聚;类核区解体和丝状染色质消失。本研究为探讨纳米TiO2光催化灭菌机理提供了直观的证据。Under the irradiation of near-UV light, the TiO_2 nanoparticles exhibit strong photocatalytic bactericidal activities. During the photocatalyic process, the ultrastructures of Escherichia coli (E. coli) have been studied in detail by transmission electron microscope (TEM). The results indicate that TiO_2 nanoparticles can act on E. coli directly and indirectly. The reactive oxygen species such as hydroxyl radical produced in the photocatalysis result in the disruption of the bacterial cell wall and cytoplasmic membrane, the leakage of the cell contents and the agglomeration of cytoplasmic matrix. The disaggregated nucleoid, the disappeared chromosome DNA and the decomposed of endotoxin were also observed in the killed cells of E. coli . The ultrastructural studies provide the evidence for understanding the cell killing mechanism of the TiO_2 photocatalyst.

关 键 词：二氧化钛纳米颗粒 光催化灭茵 大肠杆茵 超微结构 透射电子显微镜 

分 类 号：Q937[生物学—微生物学]