title: Effects of residual lignin and heteropolysaccharides on the bioconversion of softwood lignocellulose nanofibrils obtained by SO2-ethanol-water fractionation.
abstract: The amount of residual lignin and hemicelluloses in softwood fibers was systematically varied by SO2-ethanol-water fractionation for integrated biorefinery with nanomaterial and biofuel production. On the basis of their low energy demand in mechanical processing, the fibers were deconstructed to lignocellulose nanofibrils (LCNF) and used as substrate for bioconversion. The effect of LCNF composition on saccharification via multicomponent enzymes was investigated at different loadings. LCNF digestibility was compared with the enzyme activity measured with a quartz crystal microbalance. LCNF hydrolysis rate gradually decreased with lignin and hemicellulose concentration, both of which limited enzyme accessibility. Enzyme inhibition resulted from non-productive binding of proteins onto lignin. Near complete LCNF hydrolysis was achieved, even at high lignin and hemicellulose content. Sugar yields for LCNF were higher than those for precursor SEW fibers, highlighting the benefits of high surface area in LCNF.
authors.affiliation: Department of Forest Products Technology, Aalto University, School of Chemical Technology, 00076 Aalto, Finland.
authors.forename: Luis O
authors.initials: LO
authors.lastname: Morales
authors.affiliation: Department of Forest Products Technology, Aalto University, School of Chemical Technology, 00076 Aalto, Finland.
authors.forename: Mikhail
authors.initials: M
authors.lastname: Iakovlev
authors.affiliation: Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria INIA, Carretera de la Coruña km 7.5, 28040 Madrid, Spain.
authors.forename: Raquel
authors.initials: R
authors.lastname: Martin-Sampedro
authors.affiliation: VTT Technical Research Centre of Finland, P.O. Box 1000, 02044 VTT, Finland.
authors.forename: Jenni L
authors.initials: JL
authors.lastname: Rahikainen
authors.affiliation: Department of Forest Products Technology, Aalto University, School of Chemical Technology, 00076 Aalto, Finland.
authors.forename: Janne
authors.initials: J
authors.lastname: Laine
authors.affiliation: Department of Forest Products Technology, Aalto University, School of Chemical Technology, 00076 Aalto, Finland; Department of Chemical and Biological Engineering, University of Maine, 5737 Jenness Hall, Orono, ME 04469-5737, USA.
authors.forename: Adriaan
authors.initials: A
authors.lastname: van Heiningen
authors.affiliation: Department of Forest Products Technology, Aalto University, School of Chemical Technology, 00076 Aalto, Finland; North Carolina State University, Departments of Forest Biomaterials and Chemical and Biomolecular Engineering, Box 8005, Raleigh, NC 27695, USA. Electronic address: ojrojas@ncsu.edu.
authors.forename: Orlando J
authors.initials: OJ
authors.lastname: Rojas
mesh_terms: D005591:Chemical Fractionation; D000431:Ethanol; D006868:Hydrolysis; D008031:Lignin / Q000737:chemistry*; D057139:Nanofibers / Q000737:chemistry*; D028222:Picea; D011134:Polysaccharides / Q000737:chemistry*; D013458:Sulfur Dioxide
chemical_list: D011134:Polysaccharides; D013458:Sulfur Dioxide; C036909:lignocellulose; D000431:Ethanol; C007916:hemicellulose; D008031:Lignin
keywords: Bioconversion; Hemicelluloses; Lignocellulose nanofibrils (LCNF); Residual lignin; SO(2)–ethanol–water (SEW)