Effect of PEG4000 on cellulase catalysis in the lignocellulose saccharification processes
Effect of PEG4000 on cellulase catalysis in the lignocellulose saccharification processes
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DOI：
10.1002/jctb.2490
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发表时间：
2011
影响因子：
3.4
通讯作者：
Yuqing Zhang;Yue Feng Zhang-;L. Tang
中科院分区：
文献类型：
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作者：
Yuqing Zhang;Yue Feng Zhang-;L. Tang
背景：木质纤维素是生物质的重要来源。然而，木质纤维素转化为可发酵糖的转化率很低，并且糖化过程需要大量的酶。为了提高纤维素酶对木质纤维素的生物催化效率，将聚乙二醇（PEG 4000）添加到上述过程中。采用DNS、紫外吸收光谱和傅里叶变换红外光谱研究了PEG 4000和纤维素酶的添加顺序对木质纤维素糖化过程的影响，以及PEG 4000与纤维素二糖水解酶I（CBH I）之间的相互作用。研究结果：结果表明，PEG 4000和纤维素酶的不同添加顺序对糖化过程有较大影响，两种添加顺序均能提高糖化率。特别是在纤维素酶前添加PEG 4000，可以减少纤维素酶对木质素的浪费吸附，木质纤维素的糖化率可以显著提高。在无玉米秸秆（底物）的糖化过程中，通过紫外吸收光谱和傅立叶变换红外光谱的研究表明，PEG 4000与CBH I之间存在氢键和疏水相互作用。此外，还发现CBH I的活性随着作用时间的增加和PEG 4000在糖化过程中的添加量而降低。结论：在纤维素酶前添加PEG 4000是提高木质纤维素糖化率的合理途径。
BACKGROUND: Lignocellulose is a large source of biomass. However, the conversion ratio of lignocellulose into fermentable sugars is quite low, and the saccharification process requires lots of enzyme. In order to improve biocatalysis efficiency of cellulase for lignocellulose, poly ethylene glycol (PEG4000) is added to the above process. The effect of the order of addition of PEG4000 and cellulase on lignocellulose saccharification processes, and the interaction between PEG4000 and eocellobiohydrolase I (CBH I) were investigated by DNS, UV absorption spectra and Fourier transform infrared (FTIR) spectroscopy. RESULTS: Results show that different orders of addition of PEG4000 and cellulase have a strong influence on the saccharification process, and both orders of addition can improve the saccharification rate. In particular, the addition of PEG4000 before cellulase can reduce wasteful cellulase adsorption on the lignin, and the saccharification rate of lignocellulose can be significantly improved. Without corn stover (substrate) in the saccharification process, examinations by UV absorption spectra and FTIR demonstrate that the interactions between PEG4000 and CBH I are hydrogen bonds and hydrophobic interaction. In addition, it is found that the activity of CBH I is decreased with increasing interaction time and the amount of the PEG4000 added in the saccharification process. CONCLUSION: The addition of PEG4000 before cellulase to lignocellulose saccharification processes is a reasonable way to improve the saccharification rate of lignocellulose.