Xylose Production By Combined Autohydrolysis and Enzymatic Hydrolysis From Tobacco Stalks

Tobacco stalk remains after the harvest of leaves and is no important economic value but it is rich in xylan that can serve as a potential source for xylose and xylitol production. Generally, xylose is produced by chemical methods, but this method has several disadvantages such as use of corrosive chemicals like acid or the formation of undesired compounds. Alternatively, xylose can be produced by enzyme hydrolysis. Enzymatic hydrolysis is more specific and the reaction takes place at mild conditions and does not produce undesirable compounds. In this study, xylan rich liquors, extracted at 160°C for 1 h from tobacco stalks, were used to produce xylose with Trichoderma longibrachiatum xylanase. The optimum substrate concentrations and enzyme activity were 0.28 g waste/mL CAL and 228 U/mL, respectively. Under the optimum condition, xylose yield and selectivity were 79.8% and 1.9 g/g, respectively