紫外线消毒对大肠杆菌的损伤及复苏的研究  

Studies on the injury and reactivation of Escherichia coli under ultraviolet disinfection

作　　者：徐丽梅[1] 许鹏程[1] 张崇淼[1] 王晓昌[1] XU Li-mei;XU Peng-cheng;ZHANG Chong-miao;WANG Xiao-chang(Key Laboratory of Northwest Water Resource, Environment and Ecology Department of Environmental and Municipal Engineering, Xi’an University of Architecture and Technology, Xi’an 710055, China)

机构地区：[1]西安建筑科技大学环境与市政工程学院,西北水资源与环境生态教育部重点实验室,陕西西安710055

出　　处：《中国环境科学》2017年第7期2639-2645,共7页China Environmental Science

基　　金：国家自然科学基金资助项目(51578441);陕西省教育厅科研计划项目(15JK1442);国家水体污染控制与治理科技重大专项(2013ZX07310-001);陕西省污水处理与资源化重点科技创新团队项目(2013KCT-13)

摘　　要：调查了紫外线消毒后大肠杆菌的光复活和暗修复能力,分析了紫外线消毒对细胞膜、三磷酸腺苷以及核酸(DNA、RNA)的损伤,结合rec A的SOS损伤修复机制,阐述大肠杆菌对紫外线的响应机制.结果表明:20m J/cm2紫外线剂量下,大肠杆菌去除率为5.63-log,且经光复活和暗修复24h后,光复活和暗修复百分比分别达到0.018%和0.00042%,光复活能力明显大于暗修复能力.紫外线消毒过程DNA的损伤取决于片段长度,长片段16s rRNA的基因损伤更明显,水处理常规的紫外线消毒剂量对总ATP含量和膜的完整性影响较小,为紫外线消毒过程的复苏提供了基本保障.然而紫外线消毒对大肠杆菌的RNA损伤较严重,紫外剂量达到50mJ/cm2时,大肠杆菌失去了SOS损伤修复的能力,因此培养法检测80mJ/cm2时大肠杆菌的复苏能力极弱,recA相关的RNA的消失可用于指示微生物发生了不可逆损伤.In this study,the photoreactivation and dark repair of Escherichia coli(E.coli)was investigated.The effects of ultraviolet(UV)disinfection on membrane integrity,adenosine triphosphate(ATP)and nucleic acid(DNA,RNA)were further analyzed.The aim of our study was to explore the response pattern of E.coli to UV disinfection by combination of SOS response mechanism of recA gene.The results showed that the inactivation efficiency of E.coli reached5.63-log at a UV dose of20mJ/cm2.When the light exposure time and dark repair time was prolonged to24h after a UV dose of20mJ/cm2,the percentages of photoreactivation and dark repair observed for E.coli were0.018%and0.00042%,respectively.The ability of photoreactivation of E.coli was higher than that of dark repair.The DNA damage depended on the fragment length of genes during UV disinfection.The longer the16s rRNA gene was,the more seriously damage occurred.Conventional UV doses in wastewater treatment did not affect the amount of total ATP and membrane integrity,which provided basic guarantee for the reactivation of E.coli after UV disinfection.UV disinfection caused serious damage in recA RNA.When UV dose reached50mJ/cm2,E.coli lost the SOS response mechanism.Hence,little reactivation was observed using the culture method at a UV dose of80mJ/cm2.The lost of recA RNA could be used as an indicator for the occurrence of the irreversible injury to microorganism.

关 键 词：紫外线 复苏 膜完整性 三磷酸腺苷 DNA RNA 

分 类 号：X52[环境科学与工程—环境工程] X505