Application of antimicrobial peptides as new additives in animal nutrition

Abstract

During the past decades, a great number of antimicrobial peptides (AMPs) have been identified from a variety of species of vertebrates and invertebrates, such as magainin, aurein, cecropin, ceratotoxin, among others. Especially, the antimicrobial peptide Ctx(Ile21)-Ha, extracted and isolated from the skin secretion of an arboreal South American frog (Hypsiboas albopunctatus), has been studied and demonstrated to be a very promising molecule, due to the biological activities presented against fungus and bacteria. Regarding its property of bacterial membrane destruction and permeabilization, leading to death, those peptides are an interesting target for improvement for beef cattle nutrition and laying hens, which can be applied in animal nutrition. In this way, this project objective uses the AMP Ctx(Ile21)-Ha in the ruminant nutrition, in order to decrease the Gram-positive bacteria, harmful to the ruminal process, which decreases the animal nutrition efficiency by means of increasing the production of enteric methane. Thus, the project foresees, in addition to the synthesis of the Ctx(Ile21)-Ha peptide, an evaluation of the biological activity of the molecule against the undesirable microorganisms and, lately, in vitro e in vivo studies to verify the viability of these molecules in the ruminal liquor. In the same manner, this propose aims the evaluation of in vitro assays in monogastric animals, such as laying hens and swines, and the verification of zootechnical indexes to aim the production increase; also, analyze the peptide as a food preservative molecule, in order to increase the shelf-life. At the same time, this propose will perform peptide conjugated synthesis and specific structural modifications in primary sequence of the Ctx(Ile21)-Ha peptide, aiming the improvement and targeting the biological activity, which will result in compounds with potential antibiotic activity and able to be tested also as an additive in others animal species and verify its action on their production indexes. (AU)