State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan 430062, PR China; Hubei Key Laboratory of Industrial Biotechnology, School of Life Science, Hubei University, Wuhan 430062, PR China.
State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan 430062, PR China.
Int J Biol Macromol. 2019 Jun 15;131:676-681. doi: 10.1016/j.ijbiomac.2019.03.131. Epub 2019 Mar 20.
Natural lignocellulose is used as raw material to produce chemicals through biological transformation. The accessibility of cellulase to substrate was also one of the limiting factors of industrial production. Polyethylene glycol (PEG) can be used as additive in enzymatic hydrolysis of lignocellulose. In this study, enzymatic activity on simultaneous or non-simultaneous addition of PEG 4000 was investigated, and the partly delignified rice straw, the rice straw and filter paper were used as substrates, respectively. Enzyme activity was characterized by reducing sugar concentration in supernatant which was quantified through 3,5-dinitrosalicylic acid (DNS) method. Addition of PEG has been proven to facilitate enzymatic hydrolysis of lignocellulosic materials. Furthermore, PEG had the positive effect on hydrolytic enzyme activity of pure cellulose materials without lignin. Changes in lignocellulose materials have been observed by inverted microscope and Scanning electron microscope (SEM), and no chemical changes were shown by Fourier transform infrared spectroscopy (FTIR). The promotion of PEG on enzymatic hydrolysis of pure cellulose materials may be due to its loose physical structure and similar phenomenon in natural lignin materials. PEG loosens the physical structure of lignocellulose, thus facilitating enzymatic hydrolysis. This may be a new idea to optimize the lignocellulosic enzymatic hydrolysis process.
天然木质纤维素被用作生产化学品的原料，通过生物转化来实现。纤维素酶对底物的可及性也是工业生产的限制因素之一。聚乙二醇（PEG）可用作木质纤维素酶解的添加剂。在这项研究中，研究了同时或非同时添加 PEG4000 对酶活性的影响，分别以部分脱木质素的稻草、稻草和滤纸作为底物。通过 3,5-二硝基水杨酸（DNS）法定量上清液中的还原糖浓度来表征酶活性。研究表明，PEG 的添加有利于木质纤维素材料的酶解。此外，PEG 对不含木质素的纯纤维素材料的水解酶活性也有积极的影响。通过倒置显微镜和扫描电子显微镜（SEM）观察木质纤维素材料的变化，傅里叶变换红外光谱（FTIR）显示没有化学变化。PEG 对纯纤维素材料酶解的促进作用可能归因于其疏松的物理结构与天然木质素材料相似。PEG 疏松了木质纤维素的物理结构，从而促进了酶解。这可能是优化木质纤维素酶解过程的新思路。
