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研究了醋酸预处理对稻草主要化学成分及酶水解糖化效率的影响。在160℃下以不同的醋酸用量(0～4%)对稻草进行处理,预处理后稻草的Klason木质素含量基本保持不变,约60%的酸溶木质素被脱除;灰分含量(质量分数)约下降30%,灰分中SiO2则几乎全部保留在预处理浆料中。预处理醋酸用量的增加对酸溶木质素和灰分含量的变化均无显著影响。预处理后高聚糖的降解程度随醋酸用量的增加而上升,其中半纤维素的降解程度尤为显著,阿拉伯聚糖、半乳聚糖大量溶出。对经醋酸预处理稻草的酶水解研究表明,预处理中醋酸用量的增加无助于酶水解液中还原糖得率的提高。稻草于160℃下经不添加醋酸的自水解预处理后,其酶解还原糖得率均高于经醋酸预处理的稻草,当纤维素酶用量为40 FPU/g(对底物)时,稻草中高聚糖的酶水解转化效率最高,葡聚糖、木聚糖的转化率分别为67.8%和45.3%,总糖转化率为58.8%。
The effects of acetic acid pretreatment on the main chemical components of rice straw and enzymatic hydrolysis and saccharification efficiency were studied. The straw was treated with different acetic acid (0 ~ 4%) at 160 ℃. The content of Klason lignin remained unchanged after pretreatment, and about 60% acid lignin was removed. The ash content Fraction) decreased by about 30%, and the ash in the SiO2 is almost all retained in the pretreatment slurry. Pretreatment acetic acid increased the amount of acid-soluble lignin and ash content had no significant change. After pretreatment, the degree of degradation of the oligosaccharides increased with the increase of the amount of acetic acid, especially the degree of degradation of hemicellulose. The amounts of arabinan and galactan were greatly eluted. The enzymatic hydrolysis of straw pretreated with acetic acid showed that the increase of acetic acid in pretreatment did not contribute to the increase of the yield of reducing sugar in the enzymatic hydrolyzate. When the straw was hydrolyzed at 160 ℃ without acetic acid, the yield of enzymatic hydrolysis reduced straw was higher than straw pretreated with acetic acid. When the amount of cellulase was 40 FPU / g (substrate) The enzymatic hydrolytic conversion efficiency of high-glycan in straw was the highest, the conversion rates of glucan and xylan were 67.8% and 45.3%, respectively, and the total sugar conversion rate was 58.8%.