The invention relates to polypeptides having glucanase, e.g., endoglucanase,mannanase, xylanase activity or a combination of these activities, andpolynucleotides encoding them. In one aspect, the glucanase activity is anendoglucanase activity (e.g., endo-1,4-beta-D-glucan 4-glucano hydrolaseactivity) and comprises hydrolysis of 1,4-beta-D-glycosidic linkages incellulose, cellulose derivatives (e.g., carboxy methyl cellulose and hydroxyethyl cellulose) lichenin, beta-1,4 bonds in mixed beta-1,3 glucans, such ascereal beta-D-glucans or xyloglucans and other plant material containingcellulosic parts. In addition, methods of designing new enzymes and methods ofuse thereof are also provided. In alternative aspects, the new glucanasese.g., endoglucanases, mannanases, xylanases have increased activity andstability at increased pH and temperature.
