以基因重组技术开发木聚糖类半纤维素资源

木聚糖类半纤维素是一类取之不尽而又亟待开发利用的碳水化合物，经生物降解后所产生的木糖和少量其它单糖，可以用作基本碳源生产各种发酵产品，包括有机酸、氨基酸、单细胞蛋白、糖醇、工业酶类、溶剂或燃料醇。有关半纤维素酶及其基因的研究已经积累了很多资料，其中包括木聚糖酶、木糖苷酶、阿拉伯糖苷酶、葡萄糖醛酸酶、木聚糖乙酰酯酶以及它们的基因。通过基因重组技术可以使发酵工程菌获得降解半纤维素的能力，或者把能有效降解半纤维素的微生物构建成发酵工程菌，从而把半纤维素转化为所需求的生物工程产品。

Molecular Biotechnology in Exploiting the Resource of Hemicellulose

Hemicellulose is a kind of very abundant carbohydrate, which is not yet exploited. Xylose is the main sugar produced from biodegradation of hemicellulose, and can be used as carbon source for fermentation of organic acids, amino acids, single cell protein, alditols, enzymes, or fuels and solvents. Hemicellulases including xylanase, xylosidase, arabinosidase, glucurunidase, and acetylxylan esterase have been well characterized, and many genes encoding these enzymes have been cloned and analyzed. It is time to construct strains of recombinant genes, which can degrade hemicellulose and convert xylose to desired industrial products.