KERATIN EXTRACTION FROM POULTRY WASTE AND ASSESSMENT OF ITS ANTIBACTERIAL ACTIVITY AGAINST Staphylococcus aureus

Vargas F.S.; Chavez M.C.; Ahmed F.; Pastrana E.C.; Pastrana-Alta R.Y. · Quimica Nova (2026) · DOI: 10.21577/0100-4042.20260042

Resumen

Feathers from poultry waste, composed of approximately 90% keratin, represent an environmental burden but also a valuable source of biopolymers. This study assessed keratin extraction via a chemical reduction method. Two protocols were used: Ke-1, employing urea and sodium sulfite at pH 7 under reflux at 75 °C for 10 h, and Ke-2, which incorporated sodium dodecyl sulfate (SDS) at pH 9 for 4 h. After dialysis and lyophilization, the yields were 70% (Ke-1) and 78% (Ke-2). Fourier transform infrared spectroscopy (FTIR) spectra showed characteristic bands (amide A, I, II, III), confirming α-helix and β-sheet secondary structures. X-ray diffraction (XRD) analysis exhibited peaks at 19.03° (Ke-1) and 19.51° (Ke-2), indicating the predominance of β-sheets. Thermogravimetric analysis (TGA) revealed two thermal events: dehydration near 100 °C and degradation of the α and β structures of keratin between 240-400 °C. Micrographs obtained by scanning electron microscopy (SEM) indicated fibrillar morphology with hollow cavities, with Ke-2 displaying larger fiber diameters. The1H nuclear magnetic ressonance (NMR) spectrum confirmed signals from amino, carboxyl, methyl, and methylene groups, associated with amino acid residues of keratin. Notably, Ke-2 exhibited dose-dependent bacteriostatic activity against Staphylococcus aureus. This study demonstrates the valorization and reuse of organic residues derived from the poultry industry through an efficient and scalable processing method for converting poultry waste into high-value keratin with promising biomedical and antimicrobial applications.

Instituciones: Universidad Nacional de Ingeniería