STTR Phase I: Fungal Expression of Antimicrobial Peptides for Addition to Animal Feed

This Small Business Technology Transfer (STTR) Phase I project will develop antimicrobial peptides (AMP) as an alternative to antibiotics that are used as growth promotants in animal feed. It is common practice to add low doses of medically important antibiotics to animal feed to improve production efficiency. However, this practice has been shown to lead to antibiotic-resistant bacterial strains, which have the potential to infect humans. As an alternative to traditional antibiotics, the goal is to test the potential of antimicrobial peptides. Because antimicrobial peptides are not used for human therapy, concerns regarding bacterial resistance are significantly diminished. The key limitation in using AMP has been the inability to produce them at cost effective levels. To overcome this challenge, the first step of this project will be to express a number of different AMP in filamentous fungal fermentations, which have the potential to produce tremendous amounts of recombinant protein at greatly reduced cost. If successful, this proof-of-concept study will justify additional research to determine the efficacy of AMP in livestock. The broader impact/commercial potential of this project, if successful, is the reduction of antibiotic use in animal feeds. Some estimates place the worldwide market for animal-feed antibiotics at over $4 billion annually. However, to reduce bacterial antibiotic resistance, the FDA has recently published new guidance restricting traditional antibiotics to therapeutic use. Numerous alternatives to medically important antibiotics have been proposed, but the application of antimicrobial peptides shows great promise. The most significant limitation to their commercial application has been cost of production. Thus, the ability to economically manufacture these peptides would represent a significant benefit to the agricultural industry as it would allow farmers to maintain high levels of productivity while not generating antibiotic-resistant strains that pose a danger to humans.