Plant cell wall fractionation was performed to analyze the composition of the biomass samples44 (link),45 (link). The biomass samples were consecutively extracted to remove soluble sugars, lipids, starch, and pectin by using potassium phosphate buffer (pH 7.0), chloroform-methanol (1:1, v/v), DMSO–water (9:1, v/v), and ammonium oxalate 0.5% (w/v). The remaining crude residues were extracted with 4 M KOH containing 1.0 mg/mL sodium borohydride for 1 h at 25 °C, and the supernatants were combined as KOH-extractable hemicelluloses fraction. The remaining pellets were applied to detect total pentoses for non-KOH-extractable hemicelluloses fraction. The total hemicelluloses level was calculated by detecting pentoses of the non-KOH-extractable pellets and total hexoses and pentoses in the KOH-extractable fraction. Crystalline cellulose level was quantified using the Updegraff method33 (link). Colorimetric methods were applied for the determination of hexoses and pentoses45 (link). Total lignin was assayed using a two-step acid hydrolysis method according to the Laboratory Analytical Procedure of the National Renewable Energy Laboratory46 . GC/MS (Shimadzu GCMS-QP2010 Plus) method was applied to test monosaccharides released from enzymatic hydrolysis of pretreated lignocellulose45 (link).
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