Electrospun Polycaprolactone–Chitosan Nanofiber Scaffolds for Covalent Immobilization of Xylanase: Structural Characterization and Enzyme Performance
摘要
Xylanases (XyL) are critical enzymes that release that hydrolyze xylan, a major component of hemicellulose, into xylose and its derivates, and they are vital in diverse industrial fields. However, their use in free form is limited due to instability and lack of reusability. Enzyme immobilization offers a promising approach to overcome these drawbacks. In this study, electrospun polycaprolactone/chitosan (PCL/CHI) nanofibers were fabricated and used as by nanocarriers for covalent immobilization of XyL. A solution containing 10% PCL and 0.5% CHI in acetic acid: formic acid (6:4) was electrospun under optimized conditions (22 kV, 1 mL/h, 18 cm). Fibers were cross-linked with glutaraldehyde, washed thoroughly to remove residual toxicity, and then used for enzyme immobilization. Structural and morphological analyses (SEM, EDX, XRD, and FTIR) confirmed successful fiber formation and enzym binding. The optimum temperature was determined as 50 °C for both forms, while the optimum pH was determined as 6 for the free form and 5 for the immobilized form. The activation energy decreased from 21.46 kJ/mol to 1.17 kJ/mol, indicating enhaced catalytic efficiency. Kinetic analysis revealed a reduction in Km (13.01