Study on the inactivation effect and damage on bacteria of ultraviolet light with multi irradiance by UV-LED

Abstract It is acknowledged that the inactivation of ultraviolet has been widely used in various fields. In this article, the dose differences of various pathogenic bacteria were compared and the influence of bacterial survival state on the sterilization effect were sorting out. The effective sterilization methods and the UV sterilization mechanism of the DNA structure were explored. In the experiment, the ultraviolet (UV-C) lamp device with multi irradiance and regular irradiation was designed and assembled to carry out the irradiation experiment of bacteria. A variety of pathogenic bacteria were used in the unified culture environment and irradiation conditions, and the sterilization rate was calculated through the proliferation of bacteria after UV irradiation. The irradiation dose and dose curve of each strain to achieve the bactericidal rate were obtained. The penetration of UV to bacteria was evaluated through the killing effect of UV on colonies. The difference between bacteria and UV energy was discussed, and the influence of irradiance on inactivation effect was demonstrated. Irradiance and irradiation dose play a decisive role in the efficacy of UV sterilization. The UV dose was positively correlated with the bactericidal rate, and the bactericidal rate increased with the increase of the dose. High dose UV irradiation can kill multilayer bacteria. In the detection of bacterial damage, the UV energy in the experiment did not break the DNA fragment into small molecular bands. The ultra microstructure diagram showed that UV irradiation made the linear DNA condense, and the abnormal DNA structure could not replicate and inherit. The application of ultraviolet sterilization has a suitable energy range.