title: Lignin plays a negative role in the biochemical process for producing lignocellulosic biofuels.
abstract: A biochemical platform holds the most promising route toward lignocellulosic biofuels, in which polysaccharides are hydrolyzed by cellulase enzymes into simple sugars and fermented to ethanol by microbes. However, these polysaccharides are cross-linked in the plant cell walls with the hydrophobic network of lignin that physically impedes enzymatic deconstruction. A thermochemical pretreatment process is often required to remove or delocalize lignin, which may also generate inhibitors that hamper enzymatic hydrolysis and fermentation. Here we review recent advances in understanding lignin structure in the plant cell walls and the negative roles of lignin in the processes of converting biomass to biofuels. Perspectives and future directions to improve the biomass conversion process are also discussed.
authors.affiliation: Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401, USA.
authors.forename: Yining
authors.initials: Y
authors.lastname: Zeng
authors.affiliation: Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401, USA.
authors.forename: Shuai
authors.initials: S
authors.lastname: Zhao
authors.affiliation: National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO 80401, USA.
authors.forename: Shihui
authors.initials: S
authors.lastname: Yang
authors.affiliation: Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401, USA. Electronic address: Shi.you.Ding@nrel.gov.
authors.forename: Shi-You
authors.initials: SY
authors.lastname: Ding
mesh_terms: D056804:Biofuels / Q000600:supply & distribution*; D018533:Biomass; D002473:Cell Wall / Q000737:chemistry / Q000378:metabolism; D002480:Cellulase / Q000378:metabolism; D000431:Ethanol / Q000378:metabolism; D005285:Fermentation; D006868:Hydrolysis; D008031:Lignin / Q000737:chemistry / Q000378:metabolism*; D010944:Plants / Q000737:chemistry / Q000378:metabolism
chemical_list: D056804:Biofuels; C036909:lignocellulose; D000431:Ethanol; D008031:Lignin; D002480:Cellulase