title: Pseudo-lignin formation and its impact on enzymatic hydrolysis.
abstract: Pseudo-lignin, which can be broadly defined as aromatic material that yields a positive Klason lignin value and is not derived from native lignin, has been recently reported to form during the dilute acid pretreatment of poplar holocellulose. To investigate the chemistry of pseudo-lignin formation, GPC, FT-IR and 13C NMR were utilized to characterize pseudo-lignin extracted from dilute-acid pretreated α-cellulose and holocellulose. The results showed that pseudo-lignin consisting of carbonyl, carboxylic, aromatic and aliphatic structures was produced from dilute acid pretreated cellulose and hemicellulose. Pseudo-lignin extracted from holocellulose pretreated at different conditions had similar molecular weights (Mn∼1000 g/mol; Mw∼5000 g/mol) and structural features (carbonyl, carboxylic, aromatic and methoxy structures). These characterizations have provided the pseudo-lignin formation mechanisms during pretreatment. The presence and structure of pseudo-lignin is important since pseudo-lignin decreases the enzymatic conversion.
authors.affiliation: BioEnergy Science Center, School of Chemistry and Biochemistry, Institute of Paper Science and Technology, Georgia Institute of Technology, 500 10th Street, Atlanta, GA 30332, USA.
authors.forename: Fan
authors.initials: F
authors.lastname: Hu
authors.forename: Seokwon
authors.initials: S
authors.lastname: Jung
authors.forename: Arthur
authors.initials: A
authors.lastname: Ragauskas
mesh_terms: D001709:Biotechnology / Q000379:methods*; D050260:Carbohydrate Metabolism / Q000187:drug effects; D002480:Cellulase / Q000378:metabolism*; D002482:Cellulose / Q000378:metabolism; D005947:Glucose / Q000096:biosynthesis; D006868:Hydrolysis / Q000187:drug effects; D008031:Lignin / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D008970:Molecular Weight; D032107:Populus / Q000187:drug effects / Q000378:metabolism; D017550:Spectroscopy, Fourier Transform Infrared; D013464:Sulfuric Acids / Q000494:pharmacology; D013997:Time Factors; D001617:beta-Glucosidase / Q000378:metabolism*
chemical_list: D013464:Sulfuric Acids; D002482:Cellulose; D008031:Lignin; D001617:beta-Glucosidase; D002480:Cellulase; D005947:Glucose; C033158:sulfuric acid