title: Changes in Lignin and Polysaccharide Components in 13 Cultivars of Rice Straw following Dilute Acid Pretreatment as Studied by Solution-State 2D 1H-13C NMR.
abstract: A renewable raw material, rice straw is pretreated for biorefinery usage. Solution-state two-dimensional (2D) 1H-13 C hetero-nuclear single quantum coherence (HSQC) nuclear magnetic resonance (NMR) spectroscopy, was used to analyze 13 cultivars of rice straw before and after dilute acid pretreatment, to characterize general changes in the lignin and polysaccharide components. Intensities of most (15 of 16) peaks related to lignin aromatic regions, such as p-coumarate, guaiacyl, syringyl, p-hydroxyphenyl, and cinnamyl alcohol, and methoxyl, increased or remained unchanged after pretreatment. In contrast, intensities of most (11 of 13) peaks related to lignin aliphatic linkages or ferulate decreased. Decreased heterogeneity in the intensities of three peaks related to cellulose components in acid-insoluble residues resulted in similar glucose yield (0.45-0.59 g/g-dry biomass). Starch-derived components showed positive correlations (r = 0.71 to 0.96) with glucose, 5-hydroxymethylfurfural (5-HMF), and formate concentrations in the liquid hydrolysates, and negative correlations (r = -0.95 to -0.97) with xylose concentration and acid-insoluble residue yield. These results showed the fate of lignin and polysaccharide components by pretreatment, suggesting that lignin aromatic regions and cellulose components were retained in the acid insoluble residues and starch-derived components were transformed into glucose, 5-HMF, and formate in the liquid hydrolysate.
authors.affiliation: Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, Rokkodaicho, Nada-ku, Kobe, Hyogo, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Teramura
authors.affiliation: Organization of Advanced Science and Technology, Kobe University, Rokkodaicho, Nada-ku, Kobe, Hyogo, Japan.
authors.forename: Kengo
authors.initials: K
authors.lastname: Sasaki
authors.affiliation: Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, Rokkodaicho, Nada-ku, Kobe, Hyogo, Japan.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Oshima
authors.affiliation: Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, Rokkodaicho, Nada-ku, Kobe, Hyogo, Japan.
authors.forename: Shimpei
authors.initials: S
authors.lastname: Aikawa
authors.affiliation: Department of Bioinformatic Engineering, Graduate School of Information Science and Technology, Osaka University, Yamadaoka, Suita, Osaka, Japan; RIKEN Biomass Engineering Program, Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, Japan.
authors.forename: Fumio
authors.initials: F
authors.lastname: Matsuda
authors.affiliation: Food Resources Education and Research Center, Graduate School of Agricultural Science, Kobe University, Uzurano, Kasai, Hyogo, Japan.
authors.forename: Mami
authors.initials: M
authors.lastname: Okamoto
authors.affiliation: RIKEN Biomass Engineering Program, Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, Japan.
authors.forename: Tomokazu
authors.initials: T
authors.lastname: Shirai
authors.affiliation: Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, Rokkodaicho, Nada-ku, Kobe, Hyogo, Japan.
authors.forename: Hideo
authors.initials: H
authors.lastname: Kawaguchi
authors.affiliation: Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, Rokkodaicho, Nada-ku, Kobe, Hyogo, Japan.
authors.forename: Chiaki
authors.initials: C
authors.lastname: Ogino
authors.affiliation: Food Resources Education and Research Center, Graduate School of Agricultural Science, Kobe University, Uzurano, Kasai, Hyogo, Japan.
authors.forename: Masanori
authors.initials: M
authors.lastname: Yamasaki
authors.affiliation: RIKEN Biomass Engineering Program, Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, Japan; RIKEN Center for Sustainable Resource Science, Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, Japan; Graduate School of Medical Life Science, Yokohama City University, Suehirocho, Tsurumi-ku, Yokohama, Japan; Graduate School of Bioagricultural Sciences and School of Agricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Kikuchi
authors.affiliation: Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, Rokkodaicho, Nada-ku, Kobe, Hyogo, Japan; RIKEN Biomass Engineering Program, Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, Japan.
authors.forename: Akihiko
authors.initials: A
authors.lastname: Kondo
mesh_terms: D000143:Acids / Q000737:chemistry*; D018533:Biomass; D066241:Carbon-13 Magnetic Resonance Spectroscopy; D002480:Cellulase / Q000378:metabolism; D005561:Formates / Q000032:analysis; D005662:Furaldehyde / Q000031:analogs & derivatives / Q000032:analysis; D005947:Glucose / Q000032:analysis; D006868:Hydrolysis; D008031:Lignin / Q000737:chemistry* / Q000378:metabolism; D012275:Oryza / Q000737:chemistry / Q000378:metabolism*; D018547:Plant Stems / Q000737:chemistry / Q000378:metabolism; D011134:Polysaccharides / Q000737:chemistry* / Q000378:metabolism; D012996:Solutions / Q000737:chemistry
chemical_list: D000143:Acids; D005561:Formates; D011134:Polysaccharides; D012996:Solutions; C030544:formic acid; C008046:5-hydroxymethylfurfural; D008031:Lignin; D005662:Furaldehyde; D002480:Cellulase; D005947:Glucose