Effect of Purified Trichoderma reesei Cellulases on the Supramolecular Structure of Cotton Cellulose

Abstract

Commercial cellulases may contain mixtures of different cellulase components, and properties of cotton fabrics treated with cellulases vary with the nature of these mixtures. This study reports the effect of treatments with cellulase monocomponents on the molecular and supramolecular structures of cotton cellulose. Desized, scoured, and bleached printcloth fabrics prepared from ring spun or rotor spun Deltapine cotton yarns are treated with monocomponent cellulases—endoglucanase I and II and cellobiohydrolase I and II from Trichoderma reesei— in an acetate buffer in stainless steel canisters in the presence of stainless steel ball bearings. The effects of the treatments are reported for fabric weight loss, reducing sugar formation, fabric breaking strength and tearing strength, copper number, water of imbibition, cellulose microstructure as revealed by hydrogen bonding patterns, and fiber pore size distribution. 1 Retired.Cotton fibers consist of macrofibrils that, in turn, are composed of organized microfibrils (microcrystals). Microfibrils are formed through association of individual cellulose molecules, which form intermolecular hydrogen bonds and hydrophobic bonds [7]. The structure of the cotton fiber can be affected at any of these levels when cotton fabric is subjected to wet processing in the textile industry. ' Cellulases are used in the textile industry to improve the appearance of fabric surfaces by effecting a stonewashed appearance in denim, by biopolishing or softening fabrics, by removing surface fuzz fibers to impart a smooth appearance, or by removing &dquo;white specks&dquo; (tangled bundles of surface fibers that do not take up dyes) [12,17,24]. &dquo;Total cellulases&dquo; contain endoglucanases, exoglucanases (cellobiohydrolayses), and l3-g1ucosidases (cellobiases). The presumed mode of attack of a total cellulase on a cellulose microfibril involves synergistic action of the components of the cellulase. The endo component first clips a cellulose chain by cleaving internal glucosidic bonds, then the exo component produces cellobiose from the nonreducing end of the chains. The final step is glucose production from cellobiose by cellobiase [8,14,28]. The effects on fabric properties can vary from one monocomponent to another, i.e., one component may decrease pilling but reduce tear strength, while another component may not affect tear strength (4].Cellulase activity does not change the crystallinity index of cellulose, indicating that cellulase activity is not confined to noncrystalline regions. This mode of action supports the concept that the cellulose behaves as a one-phase polymer with crystalline regions with varying degrees of accessibility during cellulase treatment 15, 61.Extended treatment with an enzyme solution for one to seven days with agitation does not change the electron diffraction pattern until day Seven [ 16]. Our previous study reported the effect of treating a cotton fabric with a total cellulase on the molecular, supramolecular, and morphological structure of...

Biopolishing of cotton fabrics with total cellulases of Trichoderma reesei and optimization using Taguchi methods

“…1). Activity of cellulases by DNSA method showed a maximum of reducing sugar 200 μg/mL of cellulase at a temperature of 55°C, comparable to the values reported in the literatures 31–36…”

Effects of adsorption properties and mechanical agitation of two detergent cellulases towards cotton cellulose

“…The enzymatic degradation of solid cellulose is a complex process that takes place at a solid -liquid interface where the enzymes are the mobile components (Zhang & Lynd 2004). The effect of mechanical action during enzymatic treatments of cotton has been subject of numerous studies since it has implications for delivering the desired fi nishing effects (Azevedo et al 2000;Cavaco-Paulo et al 1996;Rousselle et al 2003;Timpa & Ramey 1989). Therefore, the infl uence of different levels of mechanical agitation on the action of HiCel45 and BaCel5 cellulases towards cotton was measured.…”