title: Tissue specific response of Miscanthus×giganteus to dilute acid pretreatment for enhancing cellulose digestibility.
abstract: The recalcitrance in grasses varies according to cell type and tissue. In this study, dilute acid pretreatment was performed on Miscanthus×giganteus internodes that include rind and pith regions which showing heterogeneous structural and chemical changes. Pretreatment on pith effectively hydrolyzed 73.33% hemicelluloses and separated cohesive cell walls from the compound middle lamella due to lignin migration. Lignin droplets with an average diameter of 49.5±29.3nm were concurrently coalesced on wall surface, that in turn exposed more microfibrils deep in walls to be enzymatically hydrolyzed reaching 82.55%. By contrast, the rind with a relatively intergrated cell structure was covered by larger lignin droplets (101.2±44.1nm) and filled with inaccessible microfibrils limiting enzymatic sacchrification (31.50%). Taken together, the cellulose digestibility of biomass was not majorly influenced by cellulose crystallinity, while it was strongly correlated with the positive effects of hemicelluloses degradation, lignin redistribution, cellulose exposure and loosening cell wall structure.
authors: Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing 100083, China; College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042, China.
authors: Zhe
authors: Z
authors: Ji
authors: Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing 100083, China.
authors: Xun
authors: X
authors: Zhang
authors: Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing 100083, China.
authors: Zhe
authors: Z
authors: Ling
authors: Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing 100083, China.
authors: Run-Cang
authors: RC
authors: Sun
authors: Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing 100083, China; Shandong Key Laboratory of Pulping and Papermaking Engineering, Qilu University of Technology, Jinan 250353, China. Electronic address: xfx315@bjfu.edu.cn.
authors: Feng
authors: F
authors: Xu
mesh_terms: D018533:Biomass; D002473:Cell Wall / Q000737:chemistry; D002480:Cellulase / Q000737:chemistry; D002482:Cellulose / Q000737:chemistry*; D006868:Hydrolysis; D008031:Lignin / Q000737:chemistry; D018625:Microscopy, Atomic Force; D046529:Microscopy, Electron, Transmission; D008856:Microscopy, Fluorescence; D006109:Poaceae / Q000737:chemistry*; D013464:Sulfuric Acids / Q000737:chemistry*
chemical_list: D013464:Sulfuric Acids; D002482:Cellulose; D008031:Lignin; D002480:Cellulase; C033158:sulfuric acid
keywords: Cell wall; Dilute acid pretreatment; Enzymatic hydrolysis; Miscanthus×giganteus; Pith; Rind