Unique Alternative from Dietary Saccharomyces cerevisiae Enriched with Biogenic Selenium Nanoparticles for Improving Nile Tilapia Growth and Health Performance

Abstract

Nanoparticles constantly surprise us with new and innovative applications due to their unique properties; encouraging their sustainable use in aquaculture. The fortification of aquafeeds with selenium nanoparticles (Se-NPs) provides several promises for enhancing aquatic health and other aspects of fish culturing, particularly with emergence of eco-friendly methods for synthesizing these particles by microbes, which makes their use even more exciting. Present study investigated the biosynthesis of Se-NPs with Saccharomyces cerevisiae and fortification of aquafeeds with them to stimulate Nile tilapia (Oreochromis niloticus) growth behaving, blood health and oxidative status. Firstly; Se-NPs were synthesized both intracellularly and extracellularly by Saccharomyces cerevisiae as a bioreducing agent. Characterization of Biogenic Se-NPs was done by UV-Vis spectroscopy, TEM, and SEM. After that; apparent healthy (N=135) tilapia fish (12.70± 0.15 g/fish) were partitioned randomly into three groups: group(C) had basal diet feeding as a control; while the rest two groups fed basal diet containing 10g /kg S. cerevisiae (T1) and 10g /kg S. cerevisiae/Se-NPs (T2), respectively as a fine replacement of 10 % of fish meal in fish diet. The study lasted for 60 days. The results revealed significant improvements in all growth indices (e.g. percentage increase in weight gain with 134.65% in T2 compared to 84.79% in control and in Specific growth rate with 1.42% in T2 compared to 1.02% in control), hematological indices and oxidative response (increase percentage in SOD, CAT and GSH with 16.38, 12.03 and 47.62 %, respectively and 3.93% reduction in MDA percentage) in Oreochromis niloticus fed diet containing 10g /kg S. cerevisiae/Se-NPs (T2). The biochemical indices were not significantly influenced among groups especially liver (AST and ALT) enzymes, which proved the safe, nontoxic consequence of Se-NPs administered in diets (p-value > 0.05). Thus, S. cerevisiae/Se-NPs can be a good alternative for the fine placement of 10 % of fish meal in O. niloticus diets to improve growth, hematological indices, and antioxidant- related markers.