Synthesis and application of the antimicrobial peptide Ctx(Ile21)-Ha for evaluation of the in vitro digestibility in ruminant feeding

Abstract

Many antibiotics have already been banned in several European countries, as well as in the USA. Recently, these bans are very impacting in Brazil, especially in the livestock sector, as informed by the Ministério da Agricultura, Pecuária e Abastecimento (MAPA). Faced with this new demand, this project seeks new alternatives and increases the studies on the use of natural antibiotics used as growth promoters in animal nutrition of beef cattle. As an alternative proposal, the antimicrobial peptide Ctx(Ile21)-Ha will be studied. This peptide, extracted and isolated from the Brazilian cerrado Hypsiboas albopunctus, showed biological activity against bacteria and fungi, due to its ability to permeabilize and destroy the membranes of these microorganisms. For this, the synthesis of this peptide will be performed via solid phase peptide synthesis. This methodology allows a natural molecule to be used, leaving no residues in animals that consume this compound. Subsequently, the molecule will be applied in vitro using ruminal fluid, to evaluate dry matter and neutral detergent fiber digestibility in different substrates. The peptide will be compared with antibiotics currently used in animal nutrition, such as monensin and virginiamycin. Therefore, it is expected an improvement in dry matter digestibility and fibers on ruminant fermentation processes, due to changes in microorganism populations promoted by the addition of the peptide Ctx(Ile21)-Ha, a fact that could make this molecule a promising new candidate for a efficient and natural zootechnical additive in nutrition of ruminants.