Improved Xylan Hydrolysis of Corn Stover by Deacetylation with High Solids Dilute Acid Pretreatment
Improved Xylan Hydrolysis of Corn Stover by Deacetylation with High Solids Dilute Acid Pretreatment
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DOI：
10.1021/ie201493g
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发表时间：
2012-01-11
影响因子：
4.2
通讯作者：
Tucker, Melvin
中科院分区：
文献类型：
--
作者：
Chen, Xiaowen;Shekiro, Joseph;Tucker, Melvin
为了经济有效地从玉米秸秆等草本原料中生产乙醇，必须有效地水解木聚糖，单体木糖收率接近90%。稀酸预处理是木聚糖水解的一种成熟的预处理技术；然而，中和过程中盐的积累、有毒副产物的产生以及乙酸的释放会抑制酶的糖化和发酵，导致乙醇产量下降。通过碱脱酯化成功地去除天然玉米秸秆中的乙酰基，可以潜在地提高预处理和酶解的单体木糖产量，提高纤维素的消化率，降低发酵液的细胞毒性。结果表明，碱性提取法能有效地去除玉米秸秆中的乙酰基，使高固体稀酸预处理条件下的木聚糖水解率提高50%以上，使低固体酶解条件下的木聚糖和葡聚糖水解率分别提高15%和30%。在全浆酶解中，纤维素消化率比对照组提高了30%。
To produce ethanol cost-effectively from herbaceous feedstocks such as corn stover, efficient xylan hydrolysis with monomeric xylose yields approaching 90% are necessary. Dilute acid pretreatment is well established as one of the pretreatment technologies for xylan hydrolysis; however, the accumulation of salts from neutralization, the production of toxic byproducts, and the release of acetic acid can inhibit enzymatic saccharification and fermentation, resulting in depressed ethanol yields. Successful removal of acetyl groups from native corn stover by alkali de-esterification could potentially increase monomeric xylose yields from pretreatment and enzymatic hydrolysis, improve cellulose digestibility, and reduce the cytotoxicity of the fermentation broth. Results presented in this article show that alkaline extraction removed significant amounts of acetyl groups from corn stover, improved xylan hydrolysis in high solids dilute acid pretreatment by more than 50%, and improved xylan and glucan hydrolysis in low solids enzymatic hydrolysis by 15% and 30% over control samples. In whole slurry enzymatic hydrolysis, a 30% improvement in cellulose digestibility was found over the control.