Noncovalent immobilization of cellulases using the reversibly soluble polymers for biopolishing of cotton fabric.

The hydrolytic reaction of cellulases can occur in the interior of cellulosic fibers, causing tensile strength loss of the fabrics. Cellulase immobilization is an approach to solve this problem, because enlarging the molecule size of cellulases will limit the hydrolysis to the surfaces of the fibers. In this study, commercial cellulases were noncovalently immobilized onto the reversibly soluble polymers (Eudragit S-100 and Eudragit L-100). The characteristics of cellulase-Eudragit S-100 (CES) and cellulase-Eudragit L-100 (CEL) were evaluated using Fourier transform infrared spectra, circular dichroism spectra, and fluorescence spectra. The CES showed higher stability than CEL and free cellulase, especially at higher pH and temperature. CES and CEL retained 51% and 42% of their original activities after three cycles of repeated uses, respectively. In addition, the effects of cellulase treatment on the cotton yarn and fabric have been investigated. The bending stiffness results showed that the cotton fabric samples treated with the free and immobilized cellulases were softer than untreated samples. However, less fiber damage in terms of weight loss and tensile strength of treated cotton was observed.