Antimicrobial effects of novel Hermetia illucens peptides

TL;DR

This study explores antimicrobial peptides from Black Soldier Flies and identifies one with strong antibacterial activity and low toxicity.

Contribution

The discovery of Hill_BB_C7176, a broad-spectrum antimicrobial peptide from Black Soldier Flies with low cytotoxicity.

Findings

Hill_BB_C7176 showed broad-spectrum antibacterial activity against Gram-positive and Gram-negative bacteria.

The peptide exhibited rapid bactericidal effects and strong binding to lipopolysaccharide.

In vivo tests showed improved survival in infected Galleria mellonella larvae treated with Hill_BB_C7176.

Abstract

Antimicrobial resistance represents a significant global health challenge, implicated in nearly 5 million deaths per year. This study investigates the antimicrobial properties of selected peptides derived from the Black Soldier Fly (BSF), identified in silico. Ten synthesized peptides were evaluated in vitro against Gram-positive bacteria (Staphylococcus aureus, Bacillus cereus), Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa), and fungi (Aspergillus fumigatus, Candida albicans ). Cytotoxicity was assessed using human lung fibroblasts and red blood cells. Among the peptides, Hill_BB_C7176 demonstrated broad-spectrum antibacterial activity, no cytotoxicity and low hemolytic activity (IC₅₀: 31.6 - >32 µM). The peptide displayed rapid bactericidal activity achieving complete eradication at 8× its minimal inhibitory concentration. Propidium iodide uptake increased in a concentration dependent manner, indicating membrane permeabilization contributing to antibacterial activity. In addition, Hill_BB_C7176 exhibited strong binding affinity to lipopolysaccharide (lipid A). In vivo, Hill_BB_C7176 improved survival of Galleria mellonella larvae infected with S. aureus and E. coli, showing similar survival outcomes to reference antibiotics under the experimental conditions tested. These findings highlight the antibacterial potential of BSF-derived antimicrobial peptides, particularly Hill_BB_C7176, supporting the further research on the antibacterial activity of BSF antimicrobial peptides.

The online version contains supplementary material available at 10.1038/s41598-026-40997-3.

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