Production of antibacterial Bombyx mori cecropin A in mealworm-pathogenic Beauveria bassiana ERL1170

Efforts are underway to produce antimicrobial peptides in yellow mealworms (Tenebrio molitor), which can be developed as more effective and safer animal feed additives. In this work, we expressed Bombyx mori (Bm) cecropin-A in mealworms by the infection of transformed entomopathogenic Beauveria bassiana ERL1170. The active domain of Bm cecropin A gene was tagged with a signal sequence of B. bassiana for extracellular secretion, and the fragment was inserted into ERL1170 by the restriction enzyme-mediated integration method. Transformant D-6 showed antibacterial activity against Bacillus subtilis and Listeria monocytogenes. Against T. molitor larvae, D-6 had similar mortality to wild-type, and D6-infected mealworm suspension showed strong antibacterial activity against the two bacteria, but not in the wild-type-infected mealworms, thereby increasing the value of mealworms as animal feed additives.