title: Comparative study of lignin characteristics from wheat straw obtained by soda-AQ and kraft pretreatment and effect on the following enzymatic hydrolysis process.
abstract: To understand the structural changes of lignin after soda-AQ and kraft pretreatment, milled straw lignin, black liquor lignin and residual lignin extracted from wheat straw were characterized by FT-IR, UV, GPC and NMR. The results showed that the main lignin linkages were β-aryl ether substructures (β-O-4'), followed by phenylcoumaran (β-5') and resinol (β-β') substructures, while minor content of spirodienone (β-1'), dibenzodioxocin (5-5') and α,β-diaryl ether linkages were detected as well. After pretreatment, most lignin inter-units and lignin-carbohydrate complex (LCC) linkages were degraded and dissolved in black liquor, with minor amount left in residual pretreated biomass. In addition, through quantitative (13)C and 2D-HSQC NMR spectral analysis, lignin and LCC were found to be more degraded after kraft pretreatment than soda-AQ pretreatment. Furthermore, the subsequent enzymatic hydrolysis results showed that more cellulose in wheat straw was converted to glucose after kraft pretreatment, indicating that LCC linkages were important in the enzymatic hydrolysis process.
authors.affiliation: School of Pulp & Paper Engineering, Hubei University of Technology, 430068 Wuhan, China; Institute of Paper Science and Technology, Georgia Institute of Technology, Atlanta, GA, USA.
authors.forename: Haitao
authors.initials: H
authors.lastname: Yang
authors.affiliation: School of Pulp & Paper Engineering, Hubei University of Technology, 430068 Wuhan, China.
authors.forename: Yimin
authors.initials: Y
authors.lastname: Xie
authors.affiliation: School of Pulp & Paper Engineering, Hubei University of Technology, 430068 Wuhan, China.
authors.forename: Xing
authors.initials: X
authors.lastname: Zheng
authors.affiliation: Institute of Paper Science and Technology, Georgia Institute of Technology, Atlanta, GA, USA.
authors.forename: Yunqiao
authors.initials: Y
authors.lastname: Pu
authors.affiliation: Institute of Paper Science and Technology, Georgia Institute of Technology, Atlanta, GA, USA.
authors.forename: Fang
authors.initials: F
authors.lastname: Huang
authors.affiliation: Institute of Paper Science and Technology, Georgia Institute of Technology, Atlanta, GA, USA.
authors.forename: Xianzhi
authors.initials: X
authors.lastname: Meng
authors.affiliation: Institute of Paper Science and Technology, Georgia Institute of Technology, Atlanta, GA, USA.
authors.forename: Weibing
authors.initials: W
authors.lastname: Wu
authors.affiliation: Institute of Paper Science and Technology, Georgia Institute of Technology, Atlanta, GA, USA; Department of Chemical and Biomolecular Engineering, University of Tennessee-Knoxville, Knoxville, TN, USA.
authors.forename: Arthur
authors.initials: A
authors.lastname: Ragauskas
authors.affiliation: School of Pulp & Paper Engineering, Hubei University of Technology, 430068 Wuhan, China; State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou 510640, China. Electronic address: yaolislan1982@aliyun.com.
authors.forename: Lan
authors.initials: L
authors.lastname: Yao
mesh_terms: D000880:Anthraquinones / Q000494:pharmacology*; D056804:Biofuels; D018533:Biomass; D002482:Cellulose / Q000737:chemistry* / Q000378:metabolism; D003246:Conservation of Energy Resources; D005947:Glucose / Q000378:metabolism; D006868:Hydrolysis; D008031:Lignin / Q000737:chemistry* / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D017550:Spectroscopy, Fourier Transform Infrared; D014908:Triticum / Q000737:chemistry*
chemical_list: D000880:Anthraquinones; D056804:Biofuels; D002482:Cellulose; D008031:Lignin; D005947:Glucose
keywords: Enzymatic hydrolysis; HSQC; Kraft pretreatment; Lignin; Soda-AQ pretreatment