title: Dynamic observation of the biodegradation of lignocellulosic tissue under solid-state anaerobic conditions.
abstract: The solid-state anaerobic digestion (SS-AD) of wheat straw was characterized under low inoculated batch tests during 244 days. High levels of degradation of the cellulose (52%±1) and hemicelluloses (55%±2) were observed at the final stages and associated to a methane yield of 204±16 NmL gTS(-1). Ultrastructural observations, using transmission electronic microscopy, indicated that microorganisms degraded wheat straw from the central to the outer tissue (i.e. parenchyma to epidermis), depending on cell chemical, physical accessibility and the degree of lignification. Furthermore, major degradation of sclerenchyma secondary walls was observed. The bioaccessibility of lignocellulosic structures of wheat straw is mainly limited by the external waxy layer (cuticle), tertiary cell walls, high silica content and access to the cell lumen.
authors.affiliation: INRA, UR0050, Laboratoire de Biotechnologie de l'Environnement, Avenue des Etangs, Narbonne F-11100, France.
authors.forename: J-C
authors.initials: JC
authors.lastname: Motte
authors.affiliation: Université de Lorraine, LSE, UMR 1120, Vandœuvre-lès-Nancy F-54505, France; CNRS, UMS 3562, Vandœuvre-lès-Nancy F-54501, France.
authors.forename: F
authors.initials: F
authors.lastname: Watteau
authors.affiliation: INRA, UR0050, Laboratoire de Biotechnologie de l'Environnement, Avenue des Etangs, Narbonne F-11100, France.
authors.forename: R
authors.initials: R
authors.lastname: Escudié
authors.affiliation: INRA, UR0050, Laboratoire de Biotechnologie de l'Environnement, Avenue des Etangs, Narbonne F-11100, France.
authors.forename: J-P
authors.initials: JP
authors.lastname: Steyer
authors.affiliation: INRA, UR0050, Laboratoire de Biotechnologie de l'Environnement, Avenue des Etangs, Narbonne F-11100, France.
authors.forename: N
authors.initials: N
authors.lastname: Bernet
authors.affiliation: INRA, UR0050, Laboratoire de Biotechnologie de l'Environnement, Avenue des Etangs, Narbonne F-11100, France.
authors.forename: J-P
authors.initials: JP
authors.lastname: Delgenes
authors.affiliation: INRA, UR0050, Laboratoire de Biotechnologie de l'Environnement, Avenue des Etangs, Narbonne F-11100, France; LISBP - INSA de Toulouse, INSA/CNRS 5504 - UMR INSA/INRA 792, 135 Avenue de Rangueil, 31077 Toulouse CEDEX 04, France. Electronic address: cl_dumas@insa-toulouse.fr.
authors.forename: C
authors.initials: C
authors.lastname: Dumas
mesh_terms: D000693:Anaerobiosis; D001673:Biodegradation, Environmental; D008031:Lignin / Q000378:metabolism*
chemical_list: C036909:lignocellulose; D008031:Lignin
keywords: Dry anaerobic digestion; Hydrolysis; Lignocellulosic biomass; Microbial visualizing; Transmission electronic microscopy