Two Antimicrobial Peptides Derived from Bacillus and Their Properties

Area of Science:

• Microbiology
• Biochemistry
• Animal Science

Background:

• Antibiotic overuse in animal husbandry drives antimicrobial resistance, necessitating alternatives.
• Antimicrobial peptides (AMPs) from Bacillus species offer broad-spectrum activity against resistant pathogens.
• Regulatory trends favor limiting or banning antibiotic use in livestock feed.

Purpose of the Study:

• To isolate and characterize antimicrobial peptides from Bacillus velezensis and Bacillus inaquosorum strains.
• To evaluate the efficacy and stability of these peptides as potential feed antibiotic substitutes.
• To identify novel peptide sequences for development in the animal husbandry industry.

Main Methods:

• Isolation of Bacillus velezensis 9-1 and Bacillus inaquosorum 76-1 from feed additives.
• Purification of antimicrobial peptides using ammonium sulfate precipitation, ion exchange, gel chromatography, and RP-HPLC.
• Identification of peptide molecular weight and sequences via LC-MS/MS.

Main Results:

• Two peptides, peptide-I (VFLENVLR, 988.5706 Da) and peptide-II (FSGSGSGTAFTLR, 1286.6255 Da), were purified and identified.
• Both peptides demonstrated significant antibacterial activity against Staphylococcus aureus, Bacillus cereus, and Salmonella enterica.
• Peptides exhibited excellent stability under heat, acid, alkali, and protease conditions.

Conclusions:

• Isolated antimicrobial peptides from Bacillus spp. are effective against key livestock pathogens.
• These peptides possess favorable stability profiles, making them suitable for animal feed applications.
• The identified peptides represent promising, safe alternatives to conventional antibiotics in animal husbandry.