title: UV-induced dark repair mechanisms in bacteria associated with drinking water.
abstract: Caulobacter crescentus and Aquabacterium commune, both isolated from drinking water, as well as environmental isolates of Pseudomonas aeruginosa and Enterococcus faecium were treated with different UV fluences to study their capacity to restore induced DNA damages. Here, the induction of a key mechanism of bacterial dark repair, the so-called recA system, was analysed. With newly designed probes, the specific recA mRNA was detected by Northern blot. Additionally, the RecA protein was measured by the Western blot technique using a specific antibody. In drinking water bacteria as well as in opportunistic microorganisms, a specific induction of dark repair mechanisms was found even at UV fluences higher than 400J/m(2), the German standard for UV disinfection. This induction depended on the incubation time after UV treatment. Nevertheless, the UV-induced recA expressions were found to differ in the bacteria under investigation.
authors.affiliation: Forschungszentrum Karlsruhe GmbH, Department of Environmental Microbiology, Water Technology and Geotechnology Division, Institute of Technical Chemistry, P.O. Box 3640, 76021 Karlsruhe, Germany.
authors.forename: Christina
authors.initials: C
authors.lastname: Jungfer
authors.forename: Thomas
authors.initials: T
authors.lastname: Schwartz
authors.forename: Ursula
authors.initials: U
authors.lastname: Obst
mesh_terms: D001419:Bacteria / Q000235:genetics* / Q000254:growth & development; D015152:Blotting, Northern; D015153:Blotting, Western; D016935:Caulobacter crescentus / Q000235:genetics; D004260:DNA Repair; D018076:DNA, Complementary / Q000235:genetics; D016984:Enterococcus faecium / Q000235:genetics; D011550:Pseudomonas aeruginosa / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism; D011938:Rec A Recombinases / Q000235:genetics*; D014466:Ultraviolet Rays; D014881:Water Supply
chemical_list: D018076:DNA, Complementary; D012333:RNA, Messenger; D011938:Rec A Recombinases