Simultaneous Irradiation with Different Wavelengths of Ultraviolet Light has Synergistic Bactericidal Effect on Vibrio parahaemolyticus
Mutsumi Nakahashi, Kazuaki Mawatari, Akiko Hirata, Miki Maetani, Takaaki Shimohata, Takashi Uebanso, Yasuhiro Hamada, Masatake Akutagawa, Yousuke Kinouchi and Akira Takahashi
Article first published online: 28 AUG 2014 | DOI: 10.1111/php.12309
Bactericidal damages induced by UVA (320–400 nm) and UVC (<280 nm) are different. In this study, we revealed that simultaneous irradiation with UVA-LED (365 nm) and UVC (254 nm) induced bactericidal synergistic effects and suppressed the recovery of cyclobutane pyrimidine dimers (CPDs). The synergistic effect was absent in SOS response-deficient strains, such as the recA and lexA mutants. Because recA- and lexA- mediated SOS responses have crucial roles in DNA repair pathway, the synergistic bactericidal effect produced by the simultaneous irradiation could depend on suppression of the CPDs repair. This simultaneous irradiation is a candidate new procedure for effective water disinfection.