Authors
1
Faculty of Veterinary Medicine, Amol University of Special Modern Technologies, Amol, Iran
2
Department of Pathobiology, Faculty of Veterinary Medicine, Amol University of Special Modern Technologies, Amol, Iran
3
Department of Clinical Science, Faculty of Veterinary Medicine, Amol University of Special Modern Technologies, Amol, Iran
4
Department of Microbial Biotechnology, Faculty of Biotechnology, Amol University of Special Modern Technologies, Amol, Iran
5
Department of Basic Sciences, Sari Agricultural Sciences and Natural Resources University, Sari, Iran
6
Department of Fisheries, Faculty of Natural Resources, University of Zabol, Zabol, Iran
10.22092/ijfs.2026.135846
Abstract
This study aimed to produce and evaluate the antibacterial activity of recombinant rainbow trout pro-hepcidin (rpro-RtHep). The gene sequence encoding rainbow trout pro-hepcidin was synthesized and cloned into the pET28a+ expression vector. The recombinant vector pET28a+/pro-RtHep was transformed into Escherichia coli BL21 (DE3) Rosetta for protein expression. The recombinant bacteria were cultured at 37°C and induced with 0.5 mM Isopropyl β-D-1-thiogalactopyranoside (IPTG). The presence of a 10 kDa band on SDS-PAGE confirmed successful peptide expression; subsequently, purification was carried out using affinity chromatography, and the single 10 kDa band was verified by SDS-PAGE. The biological activity of purified rpro-RtHep was evaluated by examining its inhibitory effects on the growth of selected Aeromonas hydrophila, Streptococcus iniae and Yersinia ruckeri. The results showed that rpro-RtHep effectively inhibited the growth of these bacterial species. Additionally, the survival rate of zebrafish (Danio rerio) and with the rpro-RtHep (25 µg g-1) was assessed and the results revealed that survival rate was significantly higher compared to that of the control group exposed to A. hydrophila. Immune factors, including lysozyme levels, ACH50, total protein, and total immunoglobulin demonstrated significant increases in fish injected with rpro-RtHep compared to the control group (p<0.05). The study demonstrated that rpro-RtHep protects zebrafish against A. hydrophila infection via regulating of immune factors.
Keywords
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