title: Investigating lignin key features in maize lignocelluloses using infrared spectroscopy.
abstract: Lignins and their cross-linking to hemicelluloses detrimentally affect the cellulose-to-ethanol conversion of grass lignocelluloses. Screening appropriate grass cell walls and their compositional changes during the various steps of the process calls for a high-throughput analytical technique. Such a performance can be fulfilled by Fourier transform mid-infrared (FT-MIR) spectroscopy. In the present paper, a set of maize cell walls from mature stems were selected, including brown midrib samples. Lignin fractions were isolated by mild acidolysis to obtain a set of purified maize lignin standards. The lignin content and the percentage of lignin-derived p-hydroxyphenyl (H), guaiacyl (G), and syringyl (S) thioacidolysis monomers were determined. In addition, the composition of cell wall polysaccharides, as well as the amount of ester-linked p-coumaric (CA) and ferulic (FA) acids, was measured by wet chemistry. Partial least square (PLS) analyses were applied to infrared and chemical data of cell walls. The resulting models showed a good predictive ability with regard to the lignin content, to the frequency of S (or G) thioacidolysis monomers, and to the level of ester-linked CA of maize cell walls. The loading plots and regression coefficients revealed relevant infrared absorption bands.
authors.affiliation: National Institute of Agronomic Research, UR1268 Biopolymers, Interactions, Assemblages, Nantes, 44316 France.
authors.forename: Richard
authors.initials: R
authors.lastname: Chazal
authors.forename: Paul
authors.initials: P
authors.lastname: Robert
authors.forename: Sylvie
authors.initials: S
authors.lastname: Durand
authors.forename: Marie-Françoise
authors.initials: MF
authors.lastname: Devaux
authors.forename: Luc
authors.initials: L
authors.lastname: Saulnier
authors.forename: Catherine
authors.initials: C
authors.lastname: Lapierre
authors.forename: Fabienne
authors.initials: F
authors.lastname: Guillon
mesh_terms: D008031:Lignin / Q000032:analysis / Q000737:chemistry*; D010936:Plant Extracts / Q000032:analysis / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods*; D013441:Sulfinic Acids / Q000032:analysis / Q000737:chemistry*; D013890:Thiourea / Q000031:analogs & derivatives* / Q000032:analysis / Q000737:chemistry; D003313:Zea mays / Q000737:chemistry*
chemical_list: D010936:Plant Extracts; D013441:Sulfinic Acids; C036909:lignocellulose; C047256:thiourea dioxide; C014561:formamidine sulfinic acid; D008031:Lignin; D013890:Thiourea