Demonstration of laccase-based removal of lignin from wood and non-wood plant feedstocks.
The ability of Trametes villosa laccase, in conjuction with 1-hydroxybenzotriazole (HBT) as mediator and alkaline extraction, to remove lignin was demonstrated during treatment of wood (Eucalyptus globulus) and non-wood (Pennisetum purpureum) feedstocks. At 50 Ug(-1) laccase and 2.5% HBT concentration, 48% and 32% of the Eucalyptus and Pennisetum lignin were removed, respectively. Two-dimensional nuclear magnetic resonance of the feedstocks, swollen in dimethylsulfoxide-d(6), revealed the removal of p-hydroxyphenyl, guaiacyl and syringyl lignin units and aliphatic (mainly β-O-4'-linked) side-chains of lignin, and a moderate removal of p-coumaric acid (present in Pennisetum) without a substantial change in polysaccharide cross-signals. The enzymatic pretreatment (at 25 Ug(-1)) of Eucalyptus and Pennisetum feedstocks increased the glucose (by 61% and 12% in 72 h) and ethanol (by 4 and 2 g L(-1) in 17 h) yields from both lignocellulosic materials, respectively, as compared to those without enzyme treatment.
Instituto de Recursos Naturales y Agrobiología de Sevilla, CSIC, P.O. Box 1052, E-41080 Seville, Spain. anagu@irnase.csic.es
Ana
A
Gutiérrez
Jorge
J
Rencoret
Edith M
EM
Cadena
Alejandro
A
Rico
Dorothee
D
Barth
José C
JC
del Río
Angel T
AT
Martínez
D005052:Eucalyptus / Q000737:chemistry*; D006868:Hydrolysis; D042845:Laccase / Q000737:chemistry*; D008031:Lignin / Q000302:isolation & purification*; D031782:Pennisetum / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry*; D014934:Wood / Q000737:chemistry*
D010936:Plant Extracts; D008031:Lignin; D042845:Laccase