ABSTRAKT

Atmospheric cold plasma (ACP) has been widely researched to generate function-alized solutions for decontamination of liquids and wastewater treatment. The focus of this work is the study of the ecotoxicological effects of plasma-treated water (PTW) using a free-living brown Hydra as an important and prevalent component of freshwater ecosystems. We obtained PTW by subjecting 25 mL of sterile deionized water to high-voltage (80 kV) contained ACP treatment for 15 (PTW15) and 25 (PTW25) min. With the use of a scoring procedure, we based toxicity measurements on progressive changes in Hydra morphology. The effects of PTW on Pseudomonas aeruginosa, Escherichia coli, and Bacillus atrophaeus cells were determined using a broth microdilution method that estimated minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Results demonstrated that PTW is potentially toxic to biological systems. In Hydra tests, toxic effects were observed for PTW15 and PTW25 at concentrations above 50% and 25%, respectively. Similarly, PTW25 at a concentration of 25% is lethal for P. aeruginosa and E. coli, whereas an MBC of 37.5% was obtained for B. atrophaeus. The present investigation demonstrates that Hydra can be used as an additional in vivo tool to monitor the impact of plasma-processed solutions on the aquatic environment.