Eischeid A C, Linden K G
Department of Civil and Environmental Engineering, Duke University, Durham, NC 27708-0287, USA.
J Appl Microbiol. 2007 Nov;103(5):1650-6. doi: 10.1111/j.1365-2672.2007.03424.x.
Inactivation of Escherichia coli as a function of ultraviolet (UV) wavelength was investigated by using the endonuclease-sensitive site (ESS) assay to quantify pyrimidine dimer formation.
Ultraviolet dose-response curves were determined based on both log reduction in colony-forming units (CFU) and endonuclease-sensitive sites per kb DNA (ESS/kb) for monochromatic 254-nm low-pressure (LP) UV, polychromatic medium-pressure (MP) UV, 228 and 289-nm UV irradiation. UV irradiation from LP and MP UV sources were approx. equal in both CFU reduction and pyrimidine dimer formation at all UV doses studied; 228-nm irradiation was less effective than LP or MP, and 289-nm irradiation was the least effective in both CFU reduction and pyrimidine dimer formation. These results are in qualitative agreement with the absorption spectrum of pyrimidine bases in DNA. Results indicated an approx. linear relationship between ESS/kb and log CFU reduction.
Formation of pyrimidine dimers in genomic DNA is primarily responsible for UV inactivation of E. coli.
This work contributed to fundamental understanding of UV disinfection and aids in UV reactor design.
通过使用核酸内切酶敏感位点（ESS）分析法来量化嘧啶二聚体的形成，研究大肠杆菌的紫外线（UV）波长失活情况。
基于单色254nm低压（LP）紫外线、多色中压（MP）紫外线、228nm和289nm紫外线照射下的菌落形成单位（CFU）对数减少量以及每千碱基DNA的核酸内切酶敏感位点（ESS/kb），确定紫外线剂量反应曲线。在所有研究的紫外线剂量下，LP和MP紫外线源的紫外线照射在CFU减少和嘧啶二聚体形成方面大致相同；228nm照射的效果不如LP或MP，而289nm照射在CFU减少和嘧啶二聚体形成方面效果最差。这些结果与DNA中嘧啶碱基的吸收光谱定性一致。结果表明ESS/kb与CFU对数减少之间大致呈线性关系。
基因组DNA中嘧啶二聚体的形成是大肠杆菌紫外线失活的主要原因。
这项工作有助于对紫外线消毒的基本理解，并有助于紫外线反应器的设计。
