Enhanced features of Dictyoglomus turgidum Cellulase A engineered with carbohydrate binding module 11 from Clostridium thermocellum

Lignocellulosic biomass (LCB) is a low-cost and abundant source of fermentable sugars. Enzymatic hydrolysis is one of the main ways to obtain sugars from biomass, but most of the polysaccharide-degrading enzymes are poorly efficient on LCB and cellulases with higher performances are required. In this study, we designed a chimeric protein by adding the carbohydrate binding module (CBM) of the cellulosomal enzyme CtLic26A-Cel5E (endoglucanase H or CelH) from Clostridium (Ruminiclostridium) thermocellum to the C-terminus of Dtur CelA, an interesting hyperthermostable endoglucanase from Dictyoglomus turgidum. The activity and binding rate of both native and chimeric enzyme were evaluated on soluble and insoluble polysaccharides. The addition of a CBM resulted in a cellulase with enhanced stability at extreme pHs, higher affinity and activity on insoluble cellulose.