title: The effect of isolated lignins, obtained from a range of pretreated lignocellulosic substrates, on enzymatic hydrolysis.
abstract: The influence of the residual lignin remaining in the cellulosic rich component of pretreated lignocellulosic substrates on subsequent enzymatic hydrolysis was assessed. Twelve lignin preparations were isolated by two isolation methods (protease treated lignin (PTL) and cellulolytic enzymatic lignin (CEL)) from three types of biomass (corn stover, poplar, and lodgepole pine) that had been pretreated by two processes (steam and organosolv pretreatments). Comparative analysis of the isolated lignin showed that the CEL contained lower amounts of carbohydrates and protein than did the PTL and that the isolated lignin from corn stover contained more carbohydrates than did the lignin derived from the poplar and lodgepole pine. The lower yields of acid insoluble lignin (AIL) obtained from the corn stover when using the PTL method indicated that the lignin from the corn stover had a higher hydrophilicity than did the lignin from the poplar and lodgepole pine. The isolated lignin preparations were added to the reaction mixture containing crystalline cellulose (Avicel) and their possible effects on enzymatic hydrolysis were assessed. It was apparent that the lignin isolated from lodgepole pine and steam pretreated poplar decreased the hydrolysis yields of Avicel, whereas the other isolated lignins did not appear to decrease the hydrolysis yields significantly. The hydrolysis yields of the pretreated lignocellulose and those of Avicel containing the PTL showed good correlation, indicating that the nature of the residual lignin obtained after pretreatment significantly influenced hydrolysis.
authors.affiliation: Forest Products Biotechnology, University of British Columbia, 2424 Main Mall, Vancouver, British Columbia, Canada.
authors.forename: Seiji
authors.initials: S
authors.lastname: Nakagame
authors.forename: Richard P
authors.initials: RP
authors.lastname: Chandra
authors.forename: Jack N
authors.initials: JN
authors.lastname: Saddler
mesh_terms: D018533:Biomass; D001711:Biotransformation; D002241:Carbohydrates / Q000032:analysis; D002482:Cellulose / Q000378:metabolism; D006868:Hydrolysis; D008031:Lignin / Q000737:chemistry / Q000378:metabolism*; D028223:Pinus; D032107:Populus; D011506:Proteins / Q000032:analysis; D003313:Zea mays
chemical_list: D002241:Carbohydrates; D011506:Proteins; C036909:lignocellulose; D002482:Cellulose; D008031:Lignin