Here, we aimed to produce a natural food preservative using a crude extract from edible, immunized Tenebrio molitor larvae (iTME), injected with edible bacteria using an edible solvent. Results showed that iTME had concentration-dependent inhibitory activity against food-poisoning bacteria Escherichia coli, Bacillus cereus, and Staphylococcus aureus, as well as against harmful fungi Aspergillus flavus, Aspergillus parasiticus, and Pichia anomala. Moreover, iTME showed antimicrobial activity against beneficial microorganisms Bacillus subtilis and Aspergillus oryzae, but not Lactobacillus acidophilus. Furthermore, the minimum inhibitory concentration of iTME against E. coli, B. cereus, and S. aureus was 1 mg/mL, and iTME did not lose its inhibitory activity when treated at varying temperature, pH, and salinity. In addition, the antibacterial activity was lost after reacting the iTME with trypsin and chymotrypsin. The addition of iTME to Ganjang inoculated with harmful bacteria inhibited bacterial growth. Therefore, we propose that iTME can be used as a safe natural preservative to prolong food shelf life by inhibiting the growth of food-poisoning bacteria in a variety of foods, including traditional sauces.
Keywords: aflatoxin; antimicrobial peptide; biofilm; food-poisoning bacteria; insect extract.