液氨过氧化氢联合预处理对玉米芯酶解的影响  

Effects of Combined Hydrogen Peroxide and Liquid Ammonia Treatment on Enzymatic Hydrolysis of Corn Cob

作　　者：赵超[1] 邵千钧[2,3] 曹艳[1,2] 丁为民[4] 彭何欢[1] 

机构地区：[1]浙江农林大学工程学院,杭州311300 [2]国家木质资源综合利用工程中心,杭州311300 [3]宁波大学机械工程与力学学院,宁波315211 [4]南京农业大学工学院.南京210031

出　　处：《农业机械学报》2015年第6期193-200,共8页Transactions of the Chinese Society for Agricultural Machinery

基　　金：浙江省重点科技创新团队资助项目(2011R09012-5);浙江农林大学预研资助项目(2013SWZ03)

摘　　要：为提高木质纤维原料可发酵单糖的酶解转化率,采用液氨过氧化氢联合预处理(H-LAT)玉米芯,研究了温度与过氧化氢用量比对玉米芯固体回收率、化学成分及聚糖酶解转化率的影响,并采用X射线衍射图谱和红外光谱对玉米芯H-LAT预处理前后的纤维结构特性进行了分析。结果表明:H-LAT预处理能有效地去除玉米芯中的木质素并能保留绝大部分碳水化合物;在最优的预处理条件下,添加纤维素酶、β-葡萄糖苷酶和木聚糖酶组成的复合酶系酶解72 h,玉米芯糖化率达85.0%,1 000 g干基玉米芯可获得可发酵单糖593.1 g,是未处理的3.53倍;X射线衍射表明,经H-LAT预处理后玉米芯结晶区与无定形区同步下降;红外光谱分析表明,H-LAT预处理能打破纤维素的氢键连接,破坏木质素-碳水化合物复合体内部的酯键连接,同时使残留木质素分子结构受到一定的破环,这些变化有效地降低了玉米芯的抗水解屏障,是酶解率提高的根本原因。To effectively improve the enzymatic digestibility of carbohydrates in lignocelluloses,the combined hydrogen peroxide and liquid ammonia treatment（ H-LAT） was employed as pretreatment for corn cob. The effects of temperature and H2O2 loading on solid recovery,enzymatic digestibility and lignocellulosic structure of corn cob were investigated. The results showed that the H-LAT pretreatment could effectively remove lignin and retain the most of carbohydrate in the corn cob. Enzymatic hydrolysis using cocktail enzymes including cellulase,β-glucosidase and xylanase for 72 h after pretreatment under optimal conditions,the H-LAT pretreatment achieved 85. 0% of theoretical sugar yield,and it could produce 593. 1 g fermentable monosaccharide per kilogram of dry biomass. Compared with untreated substrates,it was about 3. 53-fold in sugars yields for H-LAT treated substrates. X-ray diffraction analysis showed that the crystalline region and amorphous region of corn cob were synchronously decreased; the crystallinity changes were depended on the interaction of the two effects. Infrared spectrum analysis showed that the H-LAT pretreatment effectively broke down cellulose hydrogen bonds,and disrupted ester linkage in lignin-carbohydrate complexes. Meanwhile,lignin molecular structure was partly destructed,and the distribution of lignin produced certain changes. As a result,these changes effectively reduced the biomass recalcitrance of corn cob.

关 键 词：玉米芯 液氨 过氧化氢 预处理 酶水解 

分 类 号：TK6[动力工程及工程热物理—生物能] S216.2[农业科学—农业机械化工程]