酸碱复合处理和酶浓度对药渣纤维素水解效率的影响

Effect of acid and alkali composite pretreatment and enzyme concentration on hydrolysis efficiency of lignocellulose from dregs of decoction

为了研究酸碱复合处理对药渣木质纤维素水解效率的作用效果,探究药渣纤维素转化酶解转化乙醇的可行性,以水提药渣为原料,用NaOH-PAA进行预处理,在不同反应体系下用纤维素酶进行水解。实验结果表明,预处理后药渣酶解的葡萄糖浓度比预处理前提高3～4倍;在酶总量不变的情况下,增加底物数量和酶浓度能显著提高反应体系中的葡萄糖浓度。83～116 mg/mL的底物浓度和5.8 U/mL的酶浓度可使反应体系中的葡萄糖浓度达到12 mg/mL以上。在83 mg/mL的底物浓度和5.8 U/mL的酶浓度下,对预处理后的丹参药渣、甘草药渣及混合药渣进行纤维素酶解,60 h时,其糖产率分别为29.07 g/kg、49.31 g/kg、52.83 g/kg。结论:预处理能显著提高纤维素的酶解效率,药渣的葡萄糖产率主要取决于其纤维素含量,与药渣类型没有密切关系。

In order to study the effect of acid and alkali composite pretreatment on the hydrolysis efficiency of dregs lignocellulose,and the feasibility of conversion of dregs cellulose into ethanol,dregs from boiling water extraction of decoction were used as raw material.The dregs were pretreated by a two-stage process for delignification with alkali and peracetic acid（PAA）,and were digested in different reaction systems by cellulase.Compared with untreated dregs,the glucose concentration from alkali-PAA pretreated dregs after enzymolysis increased by 3 to 4 times.Increasing the density of substrate and enzyme in the reaction system could remarkably enhance the sugar level without increasing total enzyme amount.83 — 116 mg/mL substrate and 5.8 U/mL enzyme in the reaction system could guarantee the production of glucose over 12 mg/mL.Glucose yield from pretreated salvia dregs,licorice dregs and mixed dregs after hydrolysis for 60 h were 29.07 g/kg,49.31 g/kg,52.83 g/kg,respectively.Pretreatment could significantly improve enzymatic hydrolysis.Glucose yield of dregs was mainly determined by their cellulose content,and was not closely related with dregs type.