Application of a molecular biology concept for the detection of DNA damage and repair during UV disinfection.
As nucleic acids are major targets in bacteria during standardised UV disinfection (254 nm), inactivation rates also depend on bacterial DNA repair. Due to UV-related DNA modifications, PCR-based approaches allow for a direct detection of DNA damage and repair during UV disinfection. By applying different primer sets, the correlation between amplicon length and PCR amplification became obvious. The longer the targeted DNA fragment was, the more UV-induced DNA lesions inhibited the PCR. Regeneration of Pseudomonas aeruginosa, Enterococcus faecium, and complex wastewater communities was recorded over a time period of 66 h. While phases of intensive repair and proliferation were found for P. aeruginosa, no DNA repair was detected by qPCR in E. faecium. Cultivation experiments verified these results. Despite high UV mediated inactivation rates original wastewater bacteria seem to express an enhanced robustness against irradiation. Regeneration of dominant and proliferation of low-abundant, probably UV-resistant species contributed to a strong post-irradiation recovery accompanied by a selection for beta-Proteobacteria.
Süss
Jacqueline
J
Forschungszentrum Karlsruhe, Institute of Functional Interfaces, Microbiology of Natural and Technical Interfaces Department, Hermann-von Helmholtz-Platz 1, Eggenstein-Leopoldshafen, Germany.
Volz
Sabrina
S
Obst
Ursula
U
Schwartz
Thomas
T
D001419:Bacteria / Q000145:classification / Q000235:genetics; D015169:Colony Count, Microbial; D053938:DNA Fragmentation; D004260:DNA Repair; D004275:DNA, Ribosomal / Q000737:chemistry; D004203:Disinfection / Q000379:methods*; D016984:Enterococcus faecium / Q000254:growth & development / Q000302:isolation & purification / Q000528:radiation effects; D016133:Polymerase Chain Reaction / Q000379:methods*; D011550:Pseudomonas aeruginosa / Q000254:growth & development / Q000302:isolation & purification / Q000528:radiation effects; D014466:Ultraviolet Rays; D014865:Waste Disposal, Fluid; D014876:Water Pollution
D004275:DNA, Ribosomal