P Tour SavadKouhi - Department of Food Sciences and Technology, Science and Research Branch, Islamic Azad University, Tehran, Iran
H Ahari - Department of Food Sciences and Technology, Science and Research Branch, Islamic Azad University, Tehran, Iran
A. A Anvar - Department of Food Hygiene, Science and Research Branch, Islamic Azad University, Tehran, Iran
B Jafari - Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran

This study aimed to investigate the fungal species isolation and confirmation by the Multiplex PCR method in aquatic fish. Evaluation of the inhibitory effect of nano-essential oils of Carum copticum on isolated fungal species was also conducted in this study. The PCR results showed that ۳ out of ۵ samples were diagnosed with Fusarium solani, and two of them were positive for Saprolegnia. Moreover, in ۰.۱% of the females' nanoparticles, one peak appeared that showed a particle with an average diameter of ۳۶۰ nm, and two nanoparticles showed a peak with a mean diameter of ۲۴۲ nm. The results of minimum inhibitory concentrations (MIC) and minimum fungicidal concentrations (MFC) showed that ۰.۰۱% nano essential oil had ۰.۰۸ and ۰.۰۷ mg/ml MIC values against Fusarium solani and Saprolegnia, respectively. Gram/ml was on the growth of Fusarium solani species. The essential oils of female plants had an MIC of ۰.۰۷ in ۰.۱% essential oil and ۰.۰۳ mg/ml in ۰.۰۱% essential oil in Saprolegnia. Furthermore, in the case of ۰.۱% nano essential oil, the results showed the MIC values of ۰.۰۴ and ۰.۰۳ mg/ml against Fusarium solani and Saprolegnia, respectively. The MFC values of ۰.۱% nano essential oil were ۰.۱ and ۰.۰۷ mg/ml against Fusarium solani and Saprolegnia,respectively. It was not found on Fusarium and Saprolegnia. Overall, the results of this study using PCR for direct detection showed that ۷۰% and ۵۰% of the samples were Fusarium solani and Saprolegnia positive, respectively; therefore, the PCR was an efficient method for the detection of fungi. According to the results of nano-essential oil (۰.۱%) of females, this nano-essence had a strong inhibitory effect on Fusarium solani and Saprolegnia.

Carum copticum, fusarium, Multiplex PCR, nano-essence, Oncorhynchus mykiss, Saprolegnia