Effect of plasma-activated water, used as a disinfectant, on the hatch rate of dormant cysts of the Artemia salina

Abstract

Various disinfectants have been used to sterilize fish eggs, breeding water, and aquaculture facilities. These disinfectants exert a considerable negative effect on the environment when used in large amounts and, thus, are a public-health concern. In this study, eco-friendly plasma-activated water (PAW) was produced using non-thermal plasma technology and used as a disinfectant in an aquaculture experiment using the cysts of the Anemia salina. We used bacterial strains (Vibrio alginolyticus rm-8420, Vibrio harveyi SFC-BS, Vibrio parahaemolyticus CRS 09-17, and Edwardsiella tarda ATCC 15947) as opportunistic pathogens. The PAW rapidly reduced the number of these bacteria in cyst samples for up to 3 h after treatment, and thereafter, there was no reduction in bacterial counts. The effect was the highest in brine shrimp cyst samples inoculated with V. harveyi and treated with PAW; a similar trend was observed for the other three strains. In addition, the hatch rate of A. salina cysts infected with V. harveyi was reduced, which was recovered after PAW treatment. The cysts in the group treated with bacteria and seawater (VhS) showed a 17.6% reduction in the hatch rate relative to the control group treated with seawater, but the group inoculated with bacteria and treated with PAW showed a significant increase in the hatch rate relative to the VhS group. The results suggest that PAW can be used as an alternative disinfectant in aquaculture to sterilize fish eggs.