外源添加物强化中温碱抽提玉米秸秆渣酶解过程的研究
Enhancement Effect of Exogenous Additives on Enzymatic Conversion of Moderate Temperature Alkali-treated Corn Stover Residue
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摘要: 以中温碱抽提玉米秸秆渣为研究对象,考察了不同外源添加物对酶解工艺的辅助作用和影响机制。研究结果表明,采用中温碱抽提玉米秸秆可以脱除50.02%木质素,添加PEG6000辅助水解作用明显。当纤维素底物质量浓度40 g/L,酶用量在纤维素酶(Celluclast 1.5 L)15 FPIU/g 和纤维二糖酶(Novozyme 188)30 BU/g 水解48 h, 添加PEG6000 4.0 g/L葡萄糖得率73.51%,酶解率84.51%,较未添加样品上升幅度分别达到26.2% 和27.1%。添加PEG不仅可以减轻酶蛋白和碱抽提玉米秸秆渣的吸附,提高酶在液相中的分配,对纤维素酶活力和稳定性也具有显著的促进作用。PEG存在下纤维素酶1.5 L的滤纸酶活提高34.1%,稳定性提高57.3%。Abstract: Moderate temperature alkali-extracted corn stover was used as a substrate for enzymatic hydrolysis. The effects of diffe-rent additives on enzyme hydrolysis were investigated and their possible mechanisms were studied.The results indicated that polyethylene glycol 6000 (PEG6000) was the most effective additive. The moderate temperature alkali pretreatment resulted in decreased lignin (50.02% removal). When 40 g/L cellulose was treated by 15 FPIU/g Celluclast 1.5 L and 30 BU/g Novozyme 188 for 48 h, the sample with 73.51% glucose yield and 84.51% hydrolysis yield was obtained as 4.0 g/L PEG6000 was added, which increased 26.2% and 27.1% in contrast to the sample without PEG6000, respectively. Addition of PEG6000 reduced the adsorption of enzyme protein on alkali-extracted corn stover. On the other hand, the enzyme distribution in liquid phase, enzyme activity and stability were promoted. The cellulase activity of celluclast 1.5 L increased by 34.1% and its stability increased by 57.3% in presence of PEG.
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