Characterization of Oligomeric Xylan Structures from Corn Fiber Resistant to Pretreatment and Simultaneous Saccharification and Fermentation
Characterization of Oligomeric Xylan Structures from Corn Fiber Resistant to Pretreatment and Simultaneous Saccharification and Fermentation
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DOI：
10.1021/jf102849x
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发表时间：
2010-11-10
影响因子：
6.1
通讯作者：
Schols, Henk A.
中科院分区：
文献类型：
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作者：
Appeldoorn, Maaike M.;Kabel, Mirjam A.;Schols, Henk A.
如果由聚合葡萄糖醛酸阿拉伯木聚糖组成的半纤维素可以降解为可发酵糖，则玉米纤维是玉米工业的副产品，将成为生物乙醇生产的良好来源。需要半纤维素的结构知识来改善玉米纤维的酶水解。能够抵抗弱酸预处理和随后的酶水解的寡糖（占起始材料的 50%）在反相和尺寸排阻材料上进行分级并进行表征。每个级分中的寡糖被各种化合物高度取代。除非也存在阿魏酰基，否则含有糖醛酸的寡糖在两个极性级分中积累。含有单阿魏酸和/或二阿魏酸的阿魏酰化寡糖在另外四个非极性级分中积累。所有级分均含有大量乙酰基取代基。数据显示存在复杂的木聚糖低聚物，其中阿魏酸、二阿魏酸、乙酸、半乳糖、阿拉伯糖和糖醛酸组合在低聚物内。讨论了假设的结构，证明了缺乏哪些酶活性来完全降解玉米葡萄糖醛酸阿拉伯木聚糖。
Corn fiber, a byproduct from the corn industry, would be a good source for bioethanol production if the hemicellulose, consisting of polymeric glucoronoarabinoxylans, can be degraded into fermentable sugars. Structural knowledge of the hemicellulose is needed to improve the enzymatic hydrolyses of corn fiber. Oligosaccharides that resisted a mild acid pretreatment and subsequent enzymatic hydrolysis, representing 50% of the starting material, were fractionated on reversed phase and size exclusion material and characterized. The oligosaccharides within each fraction were highly substituted by various compounds. Oligosaccharides containing uronic acid were accumulated in two polar fractions unless also a feruloyl group was present. Feruloylated oligosaccharides, containing mono- and/or diferulic acid, were accumulated within four more apolar fractions. All fractions contained high amounts of acetyl substituents. The data show that complex xylan oligomers are present in which ferulic acid, diferulates, acetic acid, galactose, arabinose, and uronic acids were combined within an oligomer. Hypothetical structures are discussed, demonstrating which enzyme activities are lacking to fully degrade corn glucuronoarabinoxylans.