自水解预处理对稻草化学成分及酶解性能的影响

研究了自水解处理对稻草秸秆主要化学成分及酶解糖化效率的影响。结果显示:在100～160℃下对稻草进行自水解预处理,酸溶木质素的脱除程度随着自水解温度的升高而增大,而Klason木质素含量几乎没有变化,几乎全部SiO2仍然保留在预处理后草片中;稻草高聚糖的降解程度随着自水解温度的升高而增加,但由于自水解液酸性较弱,大量高聚糖仍保留在草片中;自水解预处理有利于促进稻草的酶解糖化,随着自水解预处理温度的升高和酶用量的增大,酶解液中各种聚糖得率均有不同程度的提高,但自水解温度的影响显得更为重要;经160℃自水解预处理的稻草在40 FPU/g混合酶用量下,葡聚糖和木聚糖的总转化率约为68%和45%,总糖转化率近60%。

Effects of Auto-hydrolysis of Rice Straw on Its Chemical Composition and Enzymatic Hydrolysis

The effects of auto-hydrolysis on chemical compositions and enzymatic saccharification of rice straw were investigated in this paper.The results revealed that with the increase of auto-hydrolysis temperature in the range of 100～160℃,the dissolution of acid soluble lignin went up and more polysaccharides were degraded under a higher auto-hydrolysis temperature;However,little Klason lignin was removed and almost all SiO2 and cellulose was kept in the pretreated rice straw.Auto-hydrolysis was beneficial to the enzymatic saccharification of rice straw.A higher recovery of reduced sugar in enzymatic hydrolysate would be obtained when rice straw was auto-hydrolyzed at a higher temperature and a higher enzyme loading.Auto-hydrolysis temperature took an important role in sugar recovery improvement.Glucan and xylan recovery reached up to 68% and 45%,respectively,and the total sugar recovery closed to 60% was obtained when rice straw auto-hydrolyzed at 160℃ and enzymatic hydrolysis under the load of 40 FPU/g.