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Title: An in-depth understanding of biomass recalcitrance using natural poplar variants as the feedstock

Here, in an effort to better understand the biomass recalcitrance, six natural poplar variants were selected as feedstocks based on previous sugar release analysis. Compositional analysis and physicochemical characterizations of these poplars were performed and the correlations between these physicochemical properties and enzymatic hydrolysis yield were investigated. Gel permeation chromatography (GPC) and 13C solid state NMR were used to determine the degree of polymerization (DP) and crystallinity index (CrI) of cellulose, and the results along with the sugar release study indicated that cellulose DP likely played a more important role in enzymatic hydrolysis. Simons’ stain revealed that the accessible surface area of substrate significantly varied among these variants from 17.3 to 33.2 mg g$$–1\atop{biomass}$$ as reflected by dye adsorption, and cellulose accessibility was shown as one of the major factors governing substrates digestibility. HSQC and 31P NMR analysis detailed the structural features of poplar lignin variants. Overall, cellulose relevant factors appeared to have a stronger correlation with glucose release, if any, than lignin structural features. Lignin structural features, such as a phenolic hydroxyl group and the ratio of syringyl and guaiacyl (S/G), were found to have a more convincing impact on xylose release. Low lignin content, low cellulose DP, and high cellulose accessibility generally favor enzymatic hydrolysis; however, recalcitrance cannot be simply judged on any single substrate factor.
 [1] ;  [2] ;  [2] ;  [2] ;  [3] ;  [3] ;  [4] ;  [4] ;  [2] ;  [2] ;  [2] ; ORCiD logo [5]
  1. Univ. of Tennessee, Knoxville, TN (United States)
  2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  3. Georgia Inst. of Technology, Atlanta, GA (United States)
  4. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); National Renewable Energy Lab. (NREL), Golden, CO (United States)
  5. Univ. of Tennessee, Knoxville, TN (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. Tennessee Institute of Agriculture, Knoxville, TN (United States)
Publication Date:
Report Number(s):
Journal ID: ISSN 1864-5631
Grant/Contract Number:
AC05-00OR22725; AC36-08GO28308
Accepted Manuscript
Journal Name:
Additional Journal Information:
Journal Volume: 9; Journal Issue: 00; Journal ID: ISSN 1864-5631
ChemPubSoc Europe
Research Org:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). BioEnergy Science Center (BESC); National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Org:
USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23)
Country of Publication:
United States
09 BIOMASS FUELS; biomass recalcitrance; cellulose; crystallinity; degree of polymerization; lignin
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1337507