Rosen R, Davidov Y, LaRossa R A, Belkin S
Fredy and Nadine Herrmann Graduate School of Applied Science, Hebrew University of Jerusalem, Jerusalem 91904, Israel.
Appl Biochem Biotechnol. 2000 Nov-Dec;89(2-3):151-60. doi: 10.1385/abab:89:2-3:151.
Escherichia coli strains containing plasmid-borne fusions of the recA promoter-operator region to the Vibrio fischeri lux genes were previously shown to increase their luminescence in the presence of DNA damage hazards, and thus to be useful for genotoxicant detection. The present study expands previous work by demonstrating and investigating the luminescent response of these strains to ultraviolet radiation. Several genetic variants of the basic recA'::lux design were examined, including a tolC modification of membrane efflux capacity, a chromosomal integration of the recA'::lux fusion, a different lux reporter (Photorhabdus luminescens instead of V. fischeri, allowing the assay to be run at 37 degrees C), and a different host bacterium (Salmonella typhimurium instead of E. coli). Generally, two modifications provided the fastest responses: the use of the S. typhimurium host or the P. luminescens lux reporter. Highest sensitivity, however, was demonstrated in an E. coli strain in which a single copy of the V. fischeri lux fusion was integrated into the bacterial chromosome.
先前已表明，含有recA启动子-操纵子区域与费氏弧菌lux基因的质粒融合体的大肠杆菌菌株，在存在DNA损伤危害的情况下会增强其发光能力，因此可用于遗传毒性物质检测。本研究通过证明和研究这些菌株对紫外线辐射的发光反应，扩展了先前的工作。研究了基本recA'::lux设计的几种遗传变体，包括膜外排能力的tolC修饰、recA'::lux融合体的染色体整合、不同的lux报告基因（发光杆菌属而非费氏弧菌，使检测能在37摄氏度下进行）以及不同的宿主细菌（鼠伤寒沙门氏菌而非大肠杆菌）。一般来说，有两种修饰提供了最快的反应：使用鼠伤寒沙门氏菌宿主或发光杆菌属lux报告基因。然而，在将单拷贝费氏弧菌lux融合体整合到细菌染色体中的大肠杆菌菌株中，显示出最高的灵敏度。
