Ferulate cross-links limit the enzymatic degradation of synthetically lignified primary walls of maize
Ferulate cross-links limit the enzymatic degradation of synthetically lignified primary walls of maize
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DOI：
10.1021/jf9800099
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发表时间：
1998-07-01
影响因子：
6.1
通讯作者：
Hatfield, RD
中科院分区：
文献类型：
--
作者：
Grabber, JH;Ralph, J;Hatfield, RD
阿拉伯木聚糖与木质素的阿魏酸交联可能限制结构多糖的酶促降解，从而限制禾本科作物和作物残留物作为饲料以及作为燃料和化学品生产的原料的利用。来自非木质化细胞悬浮液的玉米壁，含有约。 5.1 或 17.6 mg g(-1) 阿魏酸与松柏醇和 H2O2 合成木质化，形成脱氢聚合物-细胞壁复合物。 4.8 或 15.8 mg g(-1) 阿魏酸盐掺入木质素中。通过用 2-氨基茚满-2-膦酸培养细胞悬浮液或在复合物形成之前用重氮甲烷甲基化细胞壁阿魏酸盐，细胞壁中阿魏酸盐的浓度从正常水平降低。阿魏酸-木质素交联减少 70%，用两种真菌酶混合物水解 6 小时后碳水化合物溶解度增加 24-46%，72 小时后碳水化合物溶解度增加 0-25%。交联的减少增强了木聚糖的水解，并在较小程度上增强了壁上纤维素的水解。结果表明，减少阿拉伯木聚糖的阿魏酰化将显着改善木质化草壁的水解。
Ferulate cross-linking of arabinoxylans to lignin may restrict the enzymatic degradation of structural polysaccharides, limiting the utilization of graminaceous crops and crop residues as feedstuffs and as feedstocks for fuel and chemical production. Maize walls from nonlignified cell suspensions with ca. 5.1 or 17.6 mg g(-1) of ferulates were synthetically lignified with coniferyl alcohol and H2O2 to form dehydrogenation polymer-cell wall complexes with ca. 4.8 or 15.8 mg g(-1) of ferulates incorporated into lignin. Ferulate concentrations in cell walls were reduced from normal levels by growing cell suspensions with 2-aminoindan-2-phosphonic acid or by methylating wall ferulates with diazomethane prior to complex formation. A 70% reduction in ferulate-lignin cross-linking increased carbohydrate solubilization by 24-46% after 6 h and by 0-25% after 72 h of hydrolysis with two fungal enzyme mixtures. Reduced cross-linking enhanced the hydrolysis of xylans and, to a lesser degree, cellulose from walls. The results presented indicate that reduced feruloylation of arabinoxylans will significantly improve the hydrolysis of lignified grass walls.