高级检索+

苯氧乙醇耦合酸/碱预处理竹屑中残留木质素对其纤维素酶水解的影响

Effect of Residual Lignin on the Cellulase Hydrolysis of Bamboo Residues Pretreated with Phenoxylethanol Coupled Acid/Alkali

  • 摘要: 以竹加工剩余物竹屑为对象, 探究苯氧乙醇耦合酸/碱溶液预处理竹屑, 分析了预处理后竹屑中残留木质素的结构特性和理化性质, 并通过荧光光谱和表面等离子共振技术揭示不同方法预处理后的竹屑中残留木质素对纤维素酶的非生产性吸附机制。结果表明:随着苯氧乙醇体系中酸/碱加入, 酶解72 h预处理竹屑的纤维素酶解得率从9.39%提高到67.38%和55.41%。对残留木质素进行表征, 发现当温度升高, 木质素的紫丁香基/愈创木基结构单元(S/G)的比值增高, 且木质素相对分子质量分布更均匀。2D-HSQC NMR、31P NMR、表面电荷及疏水性等测试结果表明:木质素对纤维素酶水解的抑制作用与其酚羟基含量、疏水性和Zeta电位有关。荧光光谱和表面等离子共振技术表明:木质素与纤维素酶作用的主要驱动力类型与预处理温度、苯氧乙醇体系中酸/碱溶液的加入相关。不同预处理竹屑中木质素与纤维素酶的亲和力不同, 其中纯苯氧乙醇预处理竹屑中木质素与纤维素酶的亲和力最高, 其次为纯酸/纯碱溶液预处理的木质素, 而苯氧乙醇与酸/碱耦合预处理竹屑中木质素对纤维素酶的亲和力最低。

     

    Abstract: In this study, bamboo chips, the residue of bamboo processing, were used as the object to investigate the structural characteristics and physicochemical properties of residual lignin in bamboo chips pretreated by phenoxylethanol coupled with acid/alkali solutions. The non-productive adsorption mechanism of residual lignin on cellulase in different pretreated bamboo chips was revealed using fluorescence spectroscopy and surface plasmon resonance techniques. The results indicated that as the increases of V(phenoxylethanol) ∶ V(acid/alkali) ratio, the cellulose hydrolysis yield of pretreated bamboo chips increases from 9.39% to 67.38%/49.87%. Characterization of residual lignin revealed an increase in the syringyl/guaiacyl(S/G) ratio of lignin in pretreated bamboo chips as the temperature and the V(phenoxylethanol) ∶ V(alkali) ratio increase, and the lignin molecular weight was more uniform. The characterization results of 2D-HSQC NMR, 31P NMR, surface charge and hydrophobicity indicated that the inhibitory effect of lignin on cellulose hydrolysis was directly proportional to its phenolic hydroxyl content, hydrophobicity, and Zeta potential. Fluorescence spectroscopy and surface plasmon resonance techniques suggested that the primary driving force types for lignin-cellulase interaction were related to pretreatment temperature, phenoxylethanol volume, and acid/alkali solution volume. The affinity of lignin and cellulase from different pretreated bamboo chips was different. Among them, the highest affinity observed in pure phenoxylethanol pretreated bamboo chips, followed by pure acid/pure alkali solution pretreated lignin, and the lowest affinity was observed in phenoxylethanol and acid/alkali coupled pretreated bamboo chips.

     

/

返回文章
返回