木聚糖定向酶解与高值化转化

Directed enzymatic hydrolysis and high-value transformation of xylan

木聚糖是自然界中含量最丰富的半纤维素,占木质纤维素生物质总量的25%~35%,具有转化合成高值化产品的巨大潜力。通过对木聚糖进行定向酶解,可以获得木寡糖、木糖和阿魏酸等多种功能组分。其中,木糖和阿魏酸可以作为多种可再生燃料和化学品的前体物质被进一步转化为高值化产品,进而广泛应用于药品、化妆品、食品等领域。而木糖作为一种碳源,也可以直接用于微生物的发酵。本文首先介绍了木聚糖及其结构组成,分别描述了木聚糖水解酶及其酶解产物,进而系统综述了以木聚糖酶解产物木糖、阿拉伯糖、乙酸、阿魏酸、葡萄糖醛酸为底物生物合成不同燃料、大宗化学品、精细化学品和聚合物等高值化产品的研究进展、存在问题和解决方案,最后对木聚糖的酶解和高值化转化进行了展望。

Xylan is the most abundant hemicellulose in nature, and it accounts for 25%~35% of the total lignocellulosic biomass. Xylan has great potential in the transformation to high value-added products. Through directed enzymatic hydrolysis of xylan, multiple functional components such as xylo-oligosaccharides, xylose and ferulic acid can be obtained. Among them, xylose and ferulic acid can be used widely as precursors in food, medicine, cosmetics. Additionally, xylose is also a useful carbon source in microbial fermentation.This review firstly introduces the structural composition of xylan and the xylanolytic degradation enzymes along with the hydrolysis products, and then systematically reviews the biosynthetic progress of high valueadded products including fuels, chemicals and polymers using xylose, arabinose, acetic acid, ferulic acid and glucuronic acid as substrates. Finally, the enzymatic high-value conversion of xylan are prospected.