Influence of Cellulases on Indigo Backstaining

We have found that increasing concentrations of fungal cellulases on a fabric decrease indigo staining levels. Deletion of the cellulose binding domains (CBD) from either bacterial or fungal cellulases decreases indigo staining levels and generally causes less backstaining than the entire enzyme. Increasing the concentration of cellulases with a CBD of family I on fabric decreases indigo staining, whereas increasing the concentration of cellulase with a CBD of family II has no effect on staining. After-washing experiments of indigo-stained cotton fabrics show that it is easier to remove indigo adsorbed on cellulase adsorbed onto cotton than indigo directly adsorbed onto cotton.