hybrid approaches of thermochemical and/or chemo-catalytic breakdown of lignin
into a larger share of compounds that can be utilized for upgrading by microbial
mineralization. This ranges from the production of bio-oils and subsequent
microbial utilization of metabolizable compounds therein [162] to gasification of
lignin into syngas and subsequent gas fermentation [163]. This will allow more of
the lignin feedstock to be converted into products with a higher value than fuels,
heat, and power. In the meantime, efforts need to be made to transition lignocellulose processing as it is still predominantly performed today towards better sustainability with respect to the use of toxic chemicals, energy consumption, and
preserving value also in the lignin fraction, i.e., preserving as much as possible its
native structure for controllable and sustainable depolymerization using enzymes.
Developing a broad spectrum of enzymatic and biotechnological pathways to
marketable products from lignin and demonstrating their economic viability will
provide key arguments in this transition to more sustainable value creation from
lignin using biocatalysis.
Acknowledgements This work was supported by the project OXYMOD of the Centre for Digital
Life Norway (DLN) under Research Council of Norway grant number 269408, and the EU
Horizon 2020 project MetaFluidics with grant agreement number 685474.
References
1. Leisola M, Pastinen O, Axe DD (2012) Lignin-designed randomness. BIO-Complexity 2012
(3). https://doi.org/10.5048/BIO-C.2012.3
2. Sanderson K (2011) Lignocellulose: a chewy problem. Nature 474(7352):S12–S14. https://
doi.org/10.1038/474S012a
3. Phillips M (1934) The chemistry of lignin. Chem Rev 14(1):103–170. https://doi.org/10.
1021/cr60047a005
4. Upton BM, Kasko AM (2016) Strategies for the conversion of lignin to high-value
polymeric materials: review and perspective. Chem Rev 116(4):2275–2306. https://doi.org/
10.1021/acs.chemrev.5b00345
5. Ralph J, Lapierre C, Boerjan W (2019) Lignin structure and its engineering. Curr Opin
Biotechnol 56:240–249. https://doi.org/10.1016/j.copbio.2019.02.019
6. Li C, Zhao X, Wang A et al (2015) Catalytic transformation of lignin for the production of
chemicals and fuels. Chem Rev 115(21):11559–11624. https://doi.org/10.1021/acs.chemrev.
5b00155
7. Chio C, Sain M, Qin W (2019) Lignin utilization: a review of lignin depolymerization from
various aspects. Renew Sustain Energy Rev 107:232–249. https://doi.org/10.1016/j.rser.
2019.03.008
8. Becker J, Wittmann C (2019) A field of dreams: lignin valorization into chemicals,
materials, fuels, and health-care products. Biotechnol Adv 37(6):107360. https://doi.org/10.
1016/j.biotechadv.2019.02.016
9. Sun Z, Fridrich B, de Santi A et al (2018) Bright side of lignin depolymerization: toward
new platform chemicals. Chem Rev 118(2):614–678. https://doi.org/10.1021/acs.chemrev.
7b00588
10. Schutyser W, Renders T, Bosch SVd et al (2018) Chemicals from lignin: an interplay of
lignocellulose fractionation, depolymerisation, and upgrading. Chem Soc Rev 47(3):852–
908. https://doi.org/10.1039/C7CS00566K
462
G.-S. Nguyen et al.
into a larger share of compounds that can be utilized for upgrading by microbial
mineralization. This ranges from the production of bio-oils and subsequent
microbial utilization of metabolizable compounds therein [162] to gasification of
lignin into syngas and subsequent gas fermentation [163]. This will allow more of
the lignin feedstock to be converted into products with a higher value than fuels,
heat, and power. In the meantime, efforts need to be made to transition lignocellulose processing as it is still predominantly performed today towards better sustainability with respect to the use of toxic chemicals, energy consumption, and
preserving value also in the lignin fraction, i.e., preserving as much as possible its
native structure for controllable and sustainable depolymerization using enzymes.
Developing a broad spectrum of enzymatic and biotechnological pathways to
marketable products from lignin and demonstrating their economic viability will
provide key arguments in this transition to more sustainable value creation from
lignin using biocatalysis.
Acknowledgements This work was supported by the project OXYMOD of the Centre for Digital
Life Norway (DLN) under Research Council of Norway grant number 269408, and the EU
Horizon 2020 project MetaFluidics with grant agreement number 685474.
References
1. Leisola M, Pastinen O, Axe DD (2012) Lignin-designed randomness. BIO-Complexity 2012
(3). https://doi.org/10.5048/BIO-C.2012.3
2. Sanderson K (2011) Lignocellulose: a chewy problem. Nature 474(7352):S12–S14. https://
doi.org/10.1038/474S012a
3. Phillips M (1934) The chemistry of lignin. Chem Rev 14(1):103–170. https://doi.org/10.
1021/cr60047a005
4. Upton BM, Kasko AM (2016) Strategies for the conversion of lignin to high-value
polymeric materials: review and perspective. Chem Rev 116(4):2275–2306. https://doi.org/
10.1021/acs.chemrev.5b00345
5. Ralph J, Lapierre C, Boerjan W (2019) Lignin structure and its engineering. Curr Opin
Biotechnol 56:240–249. https://doi.org/10.1016/j.copbio.2019.02.019
6. Li C, Zhao X, Wang A et al (2015) Catalytic transformation of lignin for the production of
chemicals and fuels. Chem Rev 115(21):11559–11624. https://doi.org/10.1021/acs.chemrev.
5b00155
7. Chio C, Sain M, Qin W (2019) Lignin utilization: a review of lignin depolymerization from
various aspects. Renew Sustain Energy Rev 107:232–249. https://doi.org/10.1016/j.rser.
2019.03.008
8. Becker J, Wittmann C (2019) A field of dreams: lignin valorization into chemicals,
materials, fuels, and health-care products. Biotechnol Adv 37(6):107360. https://doi.org/10.
1016/j.biotechadv.2019.02.016
9. Sun Z, Fridrich B, de Santi A et al (2018) Bright side of lignin depolymerization: toward
new platform chemicals. Chem Rev 118(2):614–678. https://doi.org/10.1021/acs.chemrev.
7b00588
10. Schutyser W, Renders T, Bosch SVd et al (2018) Chemicals from lignin: an interplay of
lignocellulose fractionation, depolymerisation, and upgrading. Chem Soc Rev 47(3):852–
908. https://doi.org/10.1039/C7CS00566K
462
G.-S. Nguyen et al.