Chimeric cellulases (CD-CBM) show higher soluble sugar production from insoluble microcrystalline cellulose (MCC). Two insoluble substrates, microcrystalline cellulose and ionic liquid-pretreated microcrystalline cellulose, were used for this assay. a) Cel9A, Cel9Ako*, Cel9A-CBM, Cel9Ako-CBM*, CBM alone, and Cel9A + CBM untethered; b) Cel5A, Cel5Ako, Cel5A-CBM, Cel5Ako-CBM, CBM alone, and Cel5A + CBM untethered. Cellulases were loaded at 200 nM with either 50 mg/ml MCC or IL-MCC at 50°C for 24 h, and DNS assay was used to quantify sugar release with a cellobiose standard curve. *Inactive catalytic domain is indicated with the letters “ko”.