An In‐Depth Understanding of Biomass Recalcitrance Using Natural Poplar Variants as the Feedstock. Issue 1 (12th December 2016)

• Record Type: Journal Article
• Authors: Meng, Xianzhi; Pu, Yunqiao; Yoo, Chang Geun; Li, Mi; Bali, Garima; Park, Doh‐Yeon; Gjersing, Erica; Davis, Mark F.; Muchero, Wellington; Tuskan, Gerald A.; Tschaplinski, Timothy J.; Ragauskas, Arthur J.
• Is Part Of: ChemSusChem. Volume 10:Issue 1(2017)
• Page Start: 139
• Page End: 150
• Publication Date: 2016-12-12
• Subjects: biomass recalcitrance -- cellulose -- crystallinity -- degree of polymerization -- lignin; Green chemistry -- Periodicals; Sustainable engineering -- Periodicals; Chemistry -- Periodicals; Chemical engineering -- Periodicals; 660
• DOI: 10.1002/cssc.201601303
• Languages: English
• ISSNs: 1864-5631

Abstract

Abstract: 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 13 C 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 biomass as reflected by dye adsorption, and cellulose accessibility was shown as one of the major factors governing substrates digestibility. HSQC and 31 P 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. Abstract : Back to fundamentals : Biomass recalcitrance is the major barrier that significantly hindered the industrial commercialization process of converting biomass to bio‐ethanol. Cellulose and lignin structural features of various natural poplar variants are characterized, compared, and correlated with their sugar release, providing insight into most fundamental mechanisms of biomass recalcitrance.