Valduga G, Bertoloni G, Reddi E, Jori G
Department of Biology, University of Padova, Italy.
J Photochem Photobiol B. 1993 Nov;21(1):81-6. doi: 10.1016/1011-1344(93)80168-9.
In the separated surface-sensitizer system, a photosensitizer is physically separated from the substrate by a thin air layer under such conditions that only singlet oxygen can reach and oxidize the substrate, preventing the competition by type I photosensitized processes. This method has been used to study the reaction of singlet oxygen with Gram-positive (Streptococcus faecium) and Gram-negative (Escherichia coli) bacterial strains. Studies on cell samples exposed to singlet oxygen for different periods of time show a drastic decrease in survival for S. faecium, while E. coli becomes sensitive only when the integrity of the outer membrane is altered by treatment with CaCl2 or tris(hydroxymethyl)aminomethane-ethylenediaminetetraacetic acid (Tris-EDTA). Biochemical and ultrastructural analyses suggest that the cytoplasmic membrane and the genetic material are the main sites damaged by singlet oxygen.
在分离的表面敏化剂系统中，在仅单线态氧能够到达并氧化底物的条件下，光敏剂通过薄空气层与底物物理分离，从而防止I型光敏化过程的竞争。该方法已用于研究单线态氧与革兰氏阳性（粪肠球菌）和革兰氏阴性（大肠杆菌）菌株的反应。对暴露于单线态氧不同时间段的细胞样品的研究表明，粪肠球菌的存活率急剧下降，而大肠杆菌仅在通过氯化钙或三（羟甲基）氨基甲烷 - 乙二胺四乙酸（Tris - EDTA）处理改变外膜完整性时才变得敏感。生化和超微结构分析表明，细胞质膜和遗传物质是受单线态氧损伤的主要部位。
