title: How does plant cell wall nanoscale architecture correlate with enzymatic digestibility?
abstract: Greater understanding of the mechanisms contributing to chemical and enzymatic solubilization of plant cell walls is critical for enabling cost-effective industrial conversion of cellulosic biomass to biofuels. Here, we report the use of correlative imaging in real time to assess the impact of pretreatment, as well as the resulting nanometer-scale changes in cell wall structure, upon subsequent digestion by two commercially relevant cellulase systems. We demonstrate that the small, noncomplexed fungal cellulases deconstruct cell walls using mechanisms that differ considerably from those of the larger, multienzyme complexes (cellulosomes). Furthermore, high-resolution measurement of the microfibrillar architecture of cell walls suggests that digestion is primarily facilitated by enabling enzyme access to the hydrophobic cellulose face. The data support the conclusion that ideal pretreatments should maximize lignin removal and minimize polysaccharide modification, thereby retaining the essentially native microfibrillar structure.
authors.affiliation: Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401, USA. shi.you.ding@nrel.gov
authors.forename: Shi-You
authors.initials: SY
authors.lastname: Ding
authors.forename: Yu-San
authors.initials: YS
authors.lastname: Liu
authors.forename: Yining
authors.initials: Y
authors.lastname: Zeng
authors.forename: Michael E
authors.initials: ME
authors.lastname: Himmel
authors.forename: John O
authors.initials: JO
authors.lastname: Baker
authors.forename: Edward A
authors.initials: EA
authors.lastname: Bayer
mesh_terms: D002473:Cell Wall / Q000737:chemistry*; D044602:Cellulases / Q000737:chemistry*; D002482:Cellulose / Q000737:chemistry; D048013:Acetivibrio thermocellus / Q000201:enzymology*; D008031:Lignin / Q000737:chemistry; D018613:Microscopy, Confocal / Q000379:methods; D057054:Molecular Imaging; D053758:Nanoparticles / Q000737:chemistry*; D059828:Plant Cells / Q000737:chemistry*; D011134:Polysaccharides / Q000737:chemistry; D013059:Spectrum Analysis, Raman / Q000379:methods; D014242:Trichoderma / Q000201:enzymology*
chemical_list: D011134:Polysaccharides; D002482:Cellulose; D008031:Lignin; D044602:Cellulases