Shen Rui, Li Hong-Qiang, Zhang Jie, Xu Jian
National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, China.
Beijing University of Chemical Technology, Beijing, 100029, China.
Appl Biochem Biotechnol. 2016 Jul;179(5):740-52. doi: 10.1007/s12010-016-2028-5. Epub 2016 Feb 27.
As the second abundant natural carbohydrate, xylan is normally prepared through alkaline extraction and then used for xylo-oligosaccharides (XOS) production. However, the extracted xylan inevitably contains salt, ethanol, and pigment. In order to investigate the effects of these impurities on XOS production, the alkaline-extracted xylan with different kinds and concentrations of impurities was made and then hydrolyzed using alkaline xylanase (EC 3.2.1.8) to produce XOS. The results showed that a certain concentration of salt (NaCl) promoted the XOS production, while ethanol and pigment inhibited the enzymatic hydrolysis process significantly. The color value mainly ascribed to the phenolic compounds binding to xylan was a key restriction factor in the enzymatic hydrolysis later stage. Using optimal xylan sample (with 10 mg/mL NaCl, color value of 4.6 × 10(5), without ethanol) as substrate, the highest XOS yield of 58.58 % was obtained. As the substrate of XOS production, prepared xylan should contain colored materials and ethanol as less as possible, however, retains appropriate salt.
作为第二丰富的天然碳水化合物，木聚糖通常通过碱性提取制备，然后用于生产低聚木糖（XOS）。然而，提取的木聚糖不可避免地含有盐、乙醇和色素。为了研究这些杂质对XOS生产的影响，制备了含有不同种类和浓度杂质的碱性提取木聚糖，然后使用碱性木聚糖酶（EC 3.2.1.8）进行水解以生产XOS。结果表明，一定浓度的盐（NaCl）促进了XOS的生产，而乙醇和色素显著抑制了酶水解过程。主要归因于与木聚糖结合的酚类化合物的颜色值是后期酶水解的关键限制因素。以最佳木聚糖样品（含10 mg/mL NaCl，颜色值为4.6×10(5)，无乙醇）为底物，获得了58.58%的最高XOS产率。作为XOS生产的底物，制备的木聚糖应尽可能少地含有有色物质和乙醇，但要保留适当的盐。
