Abstract
UV light-emitting diode (UV-LED) was investigated in regard to the potential application to aquaculture industry. Vibrio parahaemolyticus, a pathogenic bacterium which often causes problems in the aquaculture industry, was suspended in artificial seawater or phosphate buffer saline (PBS) solution which was then irradiated by UV-LEDs with peak emission wavelength at 265, 280 or 300 nm. Inactivation efficiency was evaluated by cultivation assay. The results revealed that inactivation rate constant, k, in artificial seawater was 0.38, 0.24 and 0.02 cm2 /mJ under 265, 280, 300 nm UV-LEDs, respectively, while the k value in PBS was 0.40, 0.28 and 0.02 cm2 /mJ under 265, 280, 300 nm emmissions, respectively. Namely, the k value was highest for 265 nm UV-LED in either solution. On the other hand, electric energy consumption required for 3-log inactiveation, EEL3, in artificial seawater was 0.92, 0.42 and 4.15 kW/m3, and in PBS was 0.80, 0.41 and 4.71 kW/m3 under 265, 280 and 300 nm UV-LEDs, respectively. Thus, electrical efficiency was highest for the 280 nm UV-LED in either solution. This study provides fundamental knowledge on UV-LED applications to aquaculture industry.
