Abstract
Production of value-added compounds from a renewable aromatic polymer, lignin, has proven to be challenging. Chemical procedures, involving harsh reaction conditions, are costly and often result in nonselective degradation of lignin linkages. Therefore, enzymatic catalysis with selective cleavage of lignin bonds provides a sustainable option for lignin valorization. In this study, we describe the first functionally characterized fungal intracellular β-etherase from the wood-degrading white-rot basidiomycete Dichomitus squalens. This enzyme, Ds-GST1, from the glutathione-S-transferase superfamily selectively cleaved the β-O-4 aryl ether bond of a dimeric lignin model compound in a glutathione-dependent reaction. Ds-GST1 also demonstrated activity on polymeric synthetic lignin fractions, shown by a decrease in molecular weight distribution of the laccase-oxidized guaiacyl dehydrogenation polymer. In addition to a possible role of Ds-GST1 in intracellular catabolism of lignin-derived aromatic compounds, the cleavage of the most abundant linkages in lignin under mild reaction conditions makes this biocatalyst an attractive green alternative in biotechnological applications.
Original language | English |
---|---|
Pages (from-to) | 2878-2882 |
Journal | ACS Sustainable Chemistry & Engineering |
Volume | 6 |
Issue number | 3 |
DOIs | |
Publication status | Published - 5 Mar 2018 |
MoE publication type | A1 Journal article-refereed |
Funding
This research was supported by the European Commission Marie Curie ITN network SuBiCat FP7 (grant no: 607044) (MM), FP7 project OPTIBIOCAT (grant no: 613868) (AD), Horizon 2020 project FALCON (grant no: 720918) (PN) and the Academy of Finland (grant no: 297847) (MM, JK). The authors would like to acknowledge Dr. Francisco J. Ruiz-Dueñas, CIB-CSIC, Madrid, Spain, for providing the plasmids and E. coli strains. Ms. Janetta Salin is thanked for technical assistance.
Keywords
- Dichomitus squalens
- Glutathione- S-transferase
- Lignin
- White-rot fungi
- β- O-4 linkage
- β-Etherase