Use of ozone in the culture medium of zebrafish (Danio rerio) embryos

Abstract

In this study, we sought to demonstrate the toxicity of different concentrations of ozonated water in zebrafish embryos up to 120 hours postfertilization (hpf ) and their antimicrobial activity advantages. For the test, we placed 40 embryos per treatment in Petri dishes containing 30 ml of solution to be tested. The ozone concentrations used were calculated from an initial concentration of 72 μg/ml using the O&L 1.5 RM ozone generator (Ozone & Life, Brazil). Five serial dilutions 1:1 was performed in egg water to produce the ozone treatments. We also analyzed a treatment with 30 ml of egg water without ozone, with only the addition of methylene blue, and a treatment with 30 ml of egg water without the addition of any antifungal agent. The plates were incubated at 28 ± 1°C, and the embryos were analyzed daily until 120 hpf. The survival rate, incubation period, and possible deformities were analyzed. In addition, egg water microbiological analyses were performed to detect total coliforms and fungi and yeasts. The data were tested for normality, and analysis of variance was performed within Minitab®version 1.8 software. The results showed that there was no significant difference in embryo survival or hatching rate between treatments with different ozone concentrations (p > 0.05), and no embryonic deformities were found under any of the ozone concentrations evaluated. It can be concluded that ozone within the concentrations analyzed is not toxic to zebrafish embryos and has antifungal and antimicrobial action.