title: Effect of structural changes of lignin during the autohydrolysis and organosolv pretreatment on Eucommia ulmoides Oliver for an effective enzymatic hydrolysis.
abstract: Eucommia ulmoides Oliver (EU) wood was successively treated by autohydrolysis and organosolv pretreatment integrated process. Autohydrolysis pretreatment facilitated xylooligosaccharides production, subsequent organosolv pretreatment to obtain high-purity lignin and digestible cellulose-rich residue. Results showed that the lignin fractions obtained exhibited smaller molecular weights, narrow polydispersity, more phenolic OH groups and higher syringyl/guaiacyl ratios (S/G) than the milled wood lignin. NMR characterization of the lignin revealed that the β-O-4 linkages significantly cleaved and the structure of stilbene formed, but its resinol (β-β) was resistant to be degraded by organosolv delignification. Moreover, the glucose yield of the integrated residue achieved a maximum value of 89.3% after enzyme hydrolysis, separately about 1.0, 1.3, 3.8 times as compared to that of the ethanol organosolv residue, the hydrothermally treated residue and the EU wood, respectively, which indicated that the integrated process was a promising approach to value-added utilization of the EU wood.
authors.affiliation: College of Forestry, Northwest A&F University, Yangling 712100, China; Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing 100083, China.
authors.forename: Ming-Qiang
authors.initials: MQ
authors.lastname: Zhu
authors.affiliation: Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing 100083, China.
authors.forename: Jia-Long
authors.initials: JL
authors.lastname: Wen
authors.affiliation: College of Forestry, Northwest A&F University, Yangling 712100, China.
authors.forename: Yin-Quan
authors.initials: YQ
authors.lastname: Su
authors.affiliation: College of Forestry, Northwest A&F University, Yangling 712100, China. Electronic address: ma_wei_qin@aliyun.com.
authors.forename: Qin
authors.initials: Q
authors.lastname: Wei
authors.affiliation: Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing 100083, China.
authors.forename: Run-Cang
authors.initials: RC
authors.lastname: Sun
mesh_terms: D001709:Biotechnology; D002482:Cellulose / Q000737:chemistry; D000431:Ethanol / Q000737:chemistry; D031283:Eucommiaceae / Q000737:chemistry*; D006868:Hydrolysis; D008031:Lignin / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008970:Molecular Weight; D019800:Phenol / Q000737:chemistry; D012997:Solvents / Q000737:chemistry; D014934:Wood
chemical_list: D012997:Solvents; D019800:Phenol; D000431:Ethanol; D002482:Cellulose; D008031:Lignin
keywords: Autohydrolysis; Enzyme hydrolysis; Eucommia ulmoides Oliver; Lignin; Organosolv delignification