1. Degradation of lignin β‐aryl ether units in Arabidopsis thaliana expressing LigD, LigF and LigG from Sphingomonas paucimobilis SYK‐6
- Author
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John Ralph, Mohammed Saddik Motawie, Bodil Jørgensen, Wout Boerjan, Jesper Harholt, Ruben Vanholme, Ewelina Mnich, Fachuang Lu, Geert Goeminne, Birger Lindberg Møller, Peter Ulvskov, Nanna Bjarnholt, Paula Oyarce, and Sarah Liu
- Subjects
0106 biological sciences ,0301 basic medicine ,Magnetic Resonance Spectroscopy ,LAMBDA GLUTATHIONE TRANSFERASES ,Arabidopsis ,Plant Science ,01 natural sciences ,Lignin ,BIOMASS ,lignin modification ,chemistry.chemical_compound ,Ligβ‐aryl ether ,Gene Expression Regulation, Plant ,CELL-WALL ,Arabidopsis thaliana ,SOLUTION-STATE NMR ,bacteria ,Research Articles ,2. Zero hunger ,SP STRAIN SYK-6 ,ROLES ,Sphingomonas paucimobilis ,food and beverages ,Plants, Genetically Modified ,beta-aryl ether ,Biochemistry ,biofuel ,Genetic Engineering ,ENZYMES ,Metabolic Networks and Pathways ,Biotechnology ,Research Article ,Ether ,saccharification yield ,Biology ,complex mixtures ,Sphingomonas ,Cell wall ,03 medical and health sciences ,Hydrolysis ,Biosynthesis ,Bacterial Proteins ,BIOSYNTHESIS ,PLANTS ,Bond cleavage ,Lig ,fungi ,technology, industry, and agriculture ,Biology and Life Sciences ,biology.organism_classification ,TRANSFORMATION ,030104 developmental biology ,Glucose ,chemistry ,Agronomy and Crop Science ,010606 plant biology & botany - Abstract
Lignin is a major polymer in the secondary plant cell wall and composed of hydrophobic interlinked hydroxyphenylpropanoid units. The presence of lignin hampers conversion of plant biomass into biofuels; plants with modified lignin are therefore being investigated for increased digestibility. The bacterium Sphingomonas paucimobilis produces lignin-degrading enzymes including LigD, LigF and LigG involved in cleaving the most abundant lignin inter-unit linkage, the β-aryl ether bond. In this study, we expressed the LigD, LigF and LigG (LigDFG) genes in Arabidopsis thaliana to introduce post-lignification modifications into the lignin structure. The three enzymes were targeted to the secretory pathway. Phenolic metabolite profiling and 2D HSQC NMR of the transgenic lines showed an increase in oxidized guaiacyl and syringyl units without concomitant increase in oxidized β-aryl-ether units, showing lignin bond cleavage. Saccharification yield increased significantly in transgenic lines expressing LigDFG, showing the applicability of our approach. Additional new information on substrate specificity of the LigDFG enzymes is also provided. This article is protected by copyright. All rights reserved.
- Published
- 2016
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