Synthesis and characterization of novel compounds and determining their antifungal properties against rainbow trout pathogen, Saprolegnia sp. in vitro

Saprolegnia growth on trout eggs is a problem frequently encountered in fish hatcheries worldwide. In the present study silver nanoparticles (Ag NPs) were effectively grafted on the zeolite and bentonite framework using the chemical reduction method. Zeolite and bentonite, silver nitrate (AgNO۳), and sodium borohydride (NaBH۴) were used as inorganic solid supports, a silver precursor, and a chemical reduction agent, respectively. Silver ions were introduced into the porous zeolite through an ion-exchange path, in the external and interlamellar space of bentonite at room temperature. AgNO۳ and NaBH۴ were used as a silver precursor and reducing agent, respectively. The Ag/zeolite and Ag/bentonite nano compounds were characterized by Field Emission Scanning Electron Microscopy (FESEM), Fourier Transform Infrared (FTIR), X-ray powder diffraction (XRD), Energy-dispersive X-Ray spectroscopy (EDX) analysis. The results showed that Ag NPs form a spherical shape with uniform homogeneity in the particle size. The antifungal activity of Ag NPs in zeolites and bentonite were investigated against Saprolegnia sp. with different loads of nano composites and exposure time. All Ag/zeolite NCs and Ag/bentonite NCs were found to have antifungal activities. These results revealed that Ag NPs could be used as effective growth inhibitors in different biological systems, for instance in aquatic animal hatchery facilities.

Keywords:

Antifungal properties , Saprolegnia , Nano silver , Zeolite , Bentonite , Saprolegnia growth index