Study on the inactivation and reactivation mechanism of pathogenic bacteria in aquaculture by UVC-LED

Ultraviolet disinfection is an important method for controlling the large-scale outbreaks of diseases in aquaculture. As a novel and promising light source, ultraviolet light-emitting diode (UV-LED) has advantages safety, high efficiency no environmental pollution risks. However, it remains unclear whether UV-LEDs can replace traditional UV sources aquaculture water treatment processes. Present study aimed to investigate efficacy UVC-LEDs (265 nm) on pathogenic bacteria, specifically Aeromonas salmonicida Escherichia coli . The effects UVC-LED dose, conditions, temperature bacterial reactivation were also investigated. results showed that exposure effectively inactivated both types bacteria. To achieve 4.5-log inactivation A. E. , 24 mJ/cm 2 28 irradiation required, rate increased with increasing fluence. Both revived after disinfection, photoreactivation was significantly higher than dark reactivation. Bacterial due high-dose lower low-dose. After 72 h reactivation, rates 1 ± 0.4% 2.2 0.2%for 0.02% 0% respectively. Besides, two bacteria exhibited different correlations temperature. highest 68.7 4% at 20°C, while 53.98 2.9% 15°C 48 h. This reveals rapid efficient by UVC-LED, elucidates mechanism influencing factors UVC-LED. highlights adequate avoidance visible inhibit Our findings form reference design operation