Silver Nanoparticles Mediated-marine Fungal Amylase Improving Dicentrarchus labrax Larvae Growth Performance

Abstract

This study investigates the capability of marine Aspergillus flavus amylase (Amy) to synthesize silver nanoparticles (AgNPs) and studies its impact on Dicentrarchus labrax(sea bass)larvae growth performance. Characterization of Amy-AgNPs was carried out by FTIR, UV–Vis’s spectroscopy, and SEM. The effect of Amy-AgNPs on antimicrobial and antioxidant activities was studied. The colloidal brown color of Amy-AgNPs with FTIR analysis indicated that amylases had the responsibility for capping the produced nanoparticles and making them more stable. Spherical Amy-AgNPs had sizes of 22.88 to 26.35 nm. Significantly, Amy-AgNPs inhibited the growth of fish-tested microbes by a maximum zone of inhibition, 13-20 mm and maximum MICs ranged from 1.6 to 6.3 µg/ml. Also, it acted as scavenged DPPH by 31.46 to 94.0 %. Sea bass larval morphometric measurements including mean total length (TL), width (W), total weight (TW), larvae survival percentage (%) and specific growth rate (SGR) were recorded, compared to the control group using different concentrations (1, 5, 10, 20%) of encapsulated Amy-AgNPs during larval feeding regime for a period of four weeks. The results revealed that 5% Amy-AgNPs was significantly the most effective concentration at P < 0.05 and achieved higher survival percentages; 51±2.8% and increased the specific growth rate by 16.23±0.62%.