纤维素的酶水解糖化

Enzymatic hydrolysis of cellulose to sugar

纤维素为自然界存在最多的再生有机资源，能水解成葡萄糖，加工成食品、燃料、化工产品等。酸和酶都能催化水解，但酶法效果好，所得水解液的纯度高。多年来对于纤维素的酶法水解研究工作很多，但还有若干问题有待解决，尚未发展成适于工业生产应用的好工艺。本文扼要地综述纤维素的酶水解机理和纤维素物料的应用工艺。纤维素酶系内切葡聚糖酶、外切葡聚糖酶和β-葡萄糖甙酶的混合物，这三种酶协同起水解作用。纤维素物料不纯，还有伴生物半纤维素和木质素共同存在，需要预先处理，破坏纤维素的结晶性，提高水解效能，分离开半纤维素和木质素，加以好的利用，提高经济效益。

Cellulose is the most abundant organic renewable resource in nature, can be hydrolyzed to dextrose, an important source of food, fuel and chemicals.The hydrolysis can be achieved by acid or enzyme, but the enzymatic method is better, because of the higher yield and purity of hydrolyzate obtained.Many studies have been done on the enzymatic hydrolysis, but some problems still remain to be solved to develope a good process for industrial production. The cellulose hydrolytic mechanism and the industrial utilization of cellulosic materials are brieflyreviewed in this paper. Cellulase is a complex mixture of enzymes, endo-glucocanase, exo-glucocanase and 6-glucosidase,and the three enzymes synergistically hydrolyze cellulose to dextrose.The cellulose does not occur in a pure state,always associated with hemicellulose and lignin, and these crystalline structure is resistant to enzymatic attack. The cellulosic materials should be pretreated to destroy the crystallinity of cellulose; hemicellulose and lignin should be separated for good use, thus increasing the efficiency of hydrolysis and making the process more economical.