Lignin changes after steam explosion and laccase-mediator treatment of eucalyptus wood chips

Eucalyptus globulus chips were steam exploded followed by treatment with a laccase-mediator system (LMS) under different experimental conditions. Removal of hemicelluloses and, to a lesser extent, lignin was observed. Thermogravimetic analyses of whole meal obtained from chips before and after steam...

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Bibliographic Details
Authors: Martín-Sampedro, Raquel, Capanema, E. A., Hoeger, I., Villar, J. C., Rojas, O. J.
Format: article
Status:Versión enviada para evaluación y publicación
Publication Date:2011
Country:España
Institution:Consejo Superior de Investigaciones Científicas (CSIC)
Repository:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/289980
Online Access:http://hdl.handle.net/10261/289980
Access Level:Open access
Keyword:Eucalyptus globulus
Steam explosion
Laccase-mediator system
Thermogravimetric analyses (TGA)
Milled wood lignin (MWL)
2D NMR
HSQC
Quantitative 13C NMR
Lignin thermal properties
Tignin chemistry
Description
Summary:Eucalyptus globulus chips were steam exploded followed by treatment with a laccase-mediator system (LMS) under different experimental conditions. Removal of hemicelluloses and, to a lesser extent, lignin was observed. Thermogravimetic analyses of whole meal obtained from chips before and after steam explosion indicated an increase in lignin degradation temperature due to lignin condensation. In contrast, application of LMS treatment caused a reduction in lignin and polysaccharide degradation temperatures. Lignins were isolated from wood samples before and after each treatment and analyzed by 2D NMR and 13C NMR. An increase in carboxyl and phenolic hydroxyl groups and a significant decrease in β-O-4 structures were found in steam-exploded samples. The most relevant changes observed after laccase treatment were increased secondary OH and degree of condensation. © 2011 American Chemical Society.