title: Breakdown of cell wall nanostructure in dilute acid pretreated biomass.
abstract: The generation of bioethanol from lignocellulosic biomass holds great promise for renewable and clean energy production. A better understanding of the complex mechanisms of lignocellulose breakdown during various pretreatment methods is needed to realize this potential in a cost and energy efficient way. Here we use small-angle neutron scattering (SANS) to characterize morphological changes in switchgrass lignocellulose across molecular to submicrometer length scales resulting from the industrially relevant dilute acid pretreatment method. Our results demonstrate that dilute acid pretreatment increases the cross-sectional radius of the crystalline cellulose fibril. This change is accompanied by removal of hemicellulose and the formation of R(g) ∼ 135 A lignin aggregates. The structural signature of smooth cell wall surfaces is observed at length scales larger than 1000 A, and it remains remarkably invariable during pretreatment. This study elucidates the interplay of the different biomolecular components in the breakdown process of switchgrass by dilute acid pretreatment. The results are important for the development of efficient strategies of biomass to biofuel conversion.
authors: Center for Structural Molecular Biology and Molecular Bioscience and Biotechnology Group, Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA. pingalis@ornl.gov
authors: Sai Venkatesh
authors: SV
authors: Pingali
authors: Volker S
authors: VS
authors: Urban
authors: William T
authors: WT
authors: Heller
authors: Joseph
authors: J
authors: McGaughey
authors: Hugh
authors: H
authors: O'Neill
authors: Marcus
authors: M
authors: Foston
authors: Dean A
authors: DA
authors: Myles
authors: Arthur
authors: A
authors: Ragauskas
authors: Barbara R
authors: BR
authors: Evans
mesh_terms: D000143:Acids / Q000378:metabolism*; D018533:Biomass; D002473:Cell Wall / Q000737:chemistry* / Q000378:metabolism*; D000431:Ethanol / Q000737:chemistry; D008031:Lignin / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D049329:Nanostructures / Q000737:chemistry*; D033363:Neutron Diffraction; D008897:Panicum / Q000737:chemistry*; D053838:Scattering, Small Angle
chemical_list: D000143:Acids; C036909:lignocellulose; D000431:Ethanol; D008031:Lignin