A comparative study of different cellulase preparations in the enzymatic treatment of cotton fabrics

Twenty-nine cellulase preparations from different sources were compared in terms of their abrasive activities (the ability to remove Indigo from denim) and their ability to saccharify cellulose. No direct relationship could be found between these two abilities. The preparations were divided into three groups: (1) with a high yield of reducing sugars after 24 h hydrolysis of Avicel cellulose but low abrasive activity; (2) universal cellulases that could both effectively hydrolyze cellulose and remove Indigo from denim; and (3) cellulase samples with high abrasive activity but low saccharification ability. Cellobiohydrolase (CBH) and xylanase were purified from different fungi by chromatofocusing on a Mono P column and subjected to limited proteolysis with papain yielding cellulose-binding and core (catalytic) domains. The adsorption ability and backstaining index of both CBH and xylanase core proteins were notably lower than the respective parameters for the initial nondigested enzymes indicating that protein adsorption on the surface of cotton fibers is a crucial factor causing Indigo backstaining during the enzymatic denim washing procedure.