红柳制备低聚木糖和纤维低聚糖的研究

Research on xylo-oligosaccharides and cello-oligosaccharides preparation from Tamarix ramosissima

以固沙先锋植物红柳为原料,经蒸汽爆预处理,采用纤维素酶法水解制备低聚木糖和纤维低聚糖。将100g红柳于温度200℃、维压时间3 min条件下蒸汽爆破处理,蒸爆液中获得8.74 g低聚木糖,低聚木糖得率49.80%。红柳蒸汽爆破物料在用碱量25%(以Na2O计)、固液比1∶6(g/m L)、硫化度30%、160℃电加热油浴锅中处理90 min,木质素脱除率96.20%,纤维素回收率82.80%。蒸汽爆破-硫酸盐处理红柳于底物质量分数5%、50℃、p H为4.8条件下,经酶用量为20μmol/(min·g)的低β-葡萄糖苷酶活力纤维素酶三段水解24 h,纤维低聚糖得率49.03%,纤维素酶对纤维低聚糖的选择性60.09%。蒸汽爆破预处理适用于红柳制备低聚木糖,三段水解技术有利于预处理红柳渣制备纤维低聚糖,选择性高。

Xylo-oligosaccharides and cello-oligosaccharides are benificial for health and they are usually prepared from crops,such as corn cob. In this work,sand-fixing pioneer plant,Tamarix ramosissima,was used as the raw material for preparing the xylo-oligosaccharides and cello-oligosaccharides. The 100 g dried Tamarix ramosissima was pretreated by steam explosion at 200 ℃ for 180 s,8. 74 g xylo-oligosaccharides and 49. 8% xylo-oligosaccharides yield were obtained.When the steam-exploded Tamarix ramosissima was cooked in 25% alkali charge（Na OH ＋ Na2 S,30% sulfidity） at a ratio of solid to liquid 1∶ 6,160 ℃ for 90 min,the lignin removal and cellulose recovery were 96. 2% and 82. 8%,respectively. Three-stage enzymatic hydrolysis of steam exploded and sulfate pretreated Tamarix ramosissima by deffcientβ-glucosidase cellulase at dosage of 20 μmol /（min·g）,substrate loading 5%,50 ℃,p H 4. 8 for 24 h,the yield of cello-oligosaccharides and the selectivity of cellulase to cello-oligosaccharides were 49. 03% and 60. 09%,respectively.The results showed that the steam explosion was suitable for xylo-oligosaccharides preparation from Tamarix ramosissima,and three-stage enzymatic hydrolysis was beneficial for cello-oligosaccharides preparation from pretreated Tamarix ramosissima.