| The effect of supplementation of xylanases from Trichoderma viride was investigated on the hydrolysis efficiency of the corncob pre-treated at three different pretreatment conditions. In addition, the crystallinity and the size distribution of the residual after enzymatic hydrolysis were also examined using X-ray diffraction and laser particle sizer.It was shown that the glucose yields reached 43.73 %, 59.46 % and 69.66 %, respectively after the hydrolysis of substrate A(120℃,0.1% dilute sulfuric acid), B (175℃,0.1% dilute sulfuric acid) and C(160℃,0.1% dilute sulfuric acid, 70% ethanol) for 72 h using 15 FPU/g cellulases. The glucose yields increased 27.51 %, 17.16 % and 20.56 %, respectively after the hydrolysis of substrate A, B and C for 72 h using 15 FPU/g cellulases supplemented with 100 IU/g xylanases.The glucose mass increased 26.94 %, 15.23 % and 12.65 %, and the xylose mass 13.5 %, 6.82 % and 3.14 %, respectively after the hydrolysis of substrate A, B and C for 48 h using 15 FPU/g cellulases added individually the cellulases and xylanases with the identical amount of protein to 15 FPU/g cellulases.The sugar yield increased with the increase of xylanases. The optimal loading of xylanses was 100 IU/g. The glucose and xylose yields using the 35 FPU/g cellulases were almost equal to those using a mixture of 5FPU/g cellulases and 100 IU/g xylanases after the hydrolysis of all examined substrated for 48 h.The reducing sugars and total reducing sugar yields reached 83.79 % and 93.54 % respectively, using a mixture of 15 FPU/g cellulases and 100 U/g xylanases after the batch hydrolysis of substrate A for 72 h. Compared with those at the batch hydrolysis, the reducing sugars and total reducing sugar yields increased 39.71 % and 32.29 %, respectively, at semi-continuous process.The size distribution of hydrolysis residual showed that the addition of xylanase speeded up the fragmentation of corncob during the enzymatic hydrolysis; XRD analysis of the residual showed the crystallinity of smaller size was greater than that of the larger.Therefore, the addition of xylanases resulted in the enhancement in the hydrolysis efficiency of corncob pretreated by dilute acid. |
