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对甘蔗渣有机酸预处理、碱处理和氧化预处理过程中得到的5种木质素[乙酸木质素(AAL)、Acetosolv木质素(As L)、Milox木质素(ML)、过氧乙酸木质素(PAAL)和碱木质素(AL)]进行了结构表征,通过元素、官能团和化学组分分析、分子量测定及光谱特性分析,验证了甘蔗渣木质素为典型的H-S-G型木质素,除PAAL外其余4种木质素具有类似的结构特性,而PAAL由于过氧乙酸的氧化作用使木质素结构显著变化,从而具有较低的分子量、较高的酸溶木质素和羰基含量.将5种木质素添加至纤维素酶催化水解体系中,纤维素转化率均有不同程度降低,PAAL的抑制作用最强.结合添加木质素单体模型化合物的实验表明,酚羟基是木质素抑制纤维素酶作用的关键官能团,对羟苯基中酚羟基的抑制作用比愈创木基和紫丁香基更强.木质素对纤维素酶解的抑制作用不只是通过无效吸附纤维素酶实现,小分子的酚类降解产物也会降低纤维素的酶解转化效率.
Five kinds of lignin (AAL, Acetosolv lignin (As L), Milox lignin (ML), lignin peracetic acid (lignin) were obtained from bagasse organic acid pretreatment, alkali treatment and oxidation pretreatment. (PAAL) and alkali lignin (AL)] were characterized by elements, functional groups and chemical composition analysis, molecular weight determination and spectral characteristics of the verified bagasse lignin as a typical HSG lignin, except PAAL The other 4 kinds of lignin have similar structural characteristics, while the PAAL due to the oxidation of peracetic acid so that significant changes in lignin structure, which has a lower molecular weight, higher acid-soluble lignin and carbonyl content of 5 kinds of lignin Added to the cellulase catalytic hydrolysis system, the cellulose conversion rates were reduced to varying degrees, PAAL strongest inhibitory effect combined with the addition of lignin monomer model compounds experiments show that the phenolic hydroxyl is lignin inhibit the role of cellulase The key functional groups, the phenolic hydroxyl on the hydroxyl group than guaiacyl and lilac groups stronger.Lignin on cellulose hydrolysis inhibition not only through the adsorption of cellulase to achieve small molecules Phenolic degradation products will reduce the efficiency of enzymatic hydrolysis of cellulose conversion.