Microbial disintegration of wool: An effective and sustainable approach for keratin extraction

Keratin is an important biopolymer used to develop biomaterials for biomedical and industrial applications. Traditional keratin extraction methods involve the removal of surface lipids using organic solvents, detergents, and energy-intensive processes that often compromise the purity of the extracted keratin. In the present study, wool fibers were microbially disintegrated to isolate cortical cells, achieving a maximum yield of 61.43 % ± 2.02 % at a wool concentration of 3.5 % (w/v). The average length and diameter of the cortical cells were 93.50 ± 5.11 μm and 3.93 ± 0.36 μm, respectively. This microbial process effectively removed surface lipids and cuticle proteins, making it suitable for keratin extraction. The extracted keratin was characterized using FT-IR and XRD, confirming the presence of characteristic chemical groups. Thermal stability, assessed through DSC and TGA, demonstrated the stability of cortical cells. Secondary structure analysis revealed the presence of both α-helix and β-sheet conformations. The molecular weight of the extracted keratin was determined to be between 35 and 63 kDa, with two distinct protein bands. Additionally, the extracted keratin exhibited biocompatibility with NIH3T3 cell lines. This method provides a sustainable approach to isolating pure keratin from wool cortex for biomaterial development.