Qing Yang, Chengyi Li

（Shihezi University ）

Abstract：

In order to obtain antibacterial peptides of fly maggots with high antibacterial activity and apply them in animal husbandry as an antibiotic substitute, this study purified the crude extract of antibacterial peptides of fly maggots through G-25 and G-50 gel column chromatography to obtain antibacterial peptides of fly maggots with high antibacterial activity. Its thermal stability, repeated freeze-thaw stability and the effect of different pH on its activity were studied while determining its antibacterial activity. The results showed that the crude extract of fly larvae antimicrobial peptides had significant inhibitory effects on Escherichia coli, Staphylococcus aureus, and Salmonella; Using SDS-PAGE technology, the protein molecular weight of the purified fly maggot antimicrobial peptide was identified to be approximately 10 KD; Fly maggot antimicrobial peptides have good thermal stability; There was no significant difference in the effect of repeated freeze-thaw cycles on its antibacterial activity. After more than 8 cycles, the antibacterial activity was inhibited, but it still had antibacterial activity; The acid-base stability of fly larvae antimicrobial peptides was determined using different pH values. Within the pH range of 4.0-9.0, there was no significant difference in the antimicrobial activity of fly larvae antimicrobial peptides (P>0.05). However, when the pH reached 10.0, the antimicrobial activity significantly decreased, indicating that strong alkaline conditions can affect the antimicrobial activity of fly larvae antimicrobial peptides. This study provides a scientific basis for the further development and utilization of fly maggot antimicrobial peptides as a green antibiotic substitute in animal husbandry.

Key Words：

maggots; antimicrobial peptides; purification; bacteriostatic activity