title: Sequential lignin depolymerization by combination of biocatalytic and formic acid/formate treatment steps.
abstract: Lignin, a complex three-dimensional amorphous polymer, is considered to be a potential natural renewable resource for the production of low-molecular-weight aromatic compounds. In the present study, a novel sequential lignin treatment method consisting of a biocatalytic oxidation step followed by a formic acid-induced lignin depolymerization step was developed and optimized using response surface methodology. The biocatalytic step employed a laccase mediator system using the redox mediator 1-hydroxybenzotriazole. Laccases were immobilized on superparamagnetic nanoparticles using a sorption-assisted surface conjugation method allowing easy separation and reuse of the biocatalysts after treatment. Under optimized conditions, as much as 45 wt% of lignin could be solubilized either in aqueous solution after the first treatment or in ethyl acetate after the second (chemical) treatment. The solubilized products were found to be mainly low-molecular-weight aromatic monomers and oligomers. The process might be used for the production of low-molecular-weight soluble aromatic products that can be purified and/or upgraded applying further downstream processes.
authors.affiliation: Institute for Ecopreneurship, School of Life Sciences, University of Applied Sciences and Arts Northwestern Switzerland, Gründenstrasse 40, 4132, Muttenz, Switzerland. christoph.gasser@fhnw.ch.|Institute for Environmental Research, RWTH Aachen, Worringerweg 1, 52074, Aachen, Germany. christoph.gasser@fhnw.ch.
authors.forename: Christoph A
authors.initials: CA
authors.lastname: Gasser
authors.affiliation: Institute for Ecopreneurship, School of Life Sciences, University of Applied Sciences and Arts Northwestern Switzerland, Gründenstrasse 40, 4132, Muttenz, Switzerland.
authors.forename: Monika
authors.initials: M
authors.lastname: Čvančarová
authors.affiliation: Institute for Ecopreneurship, School of Life Sciences, University of Applied Sciences and Arts Northwestern Switzerland, Gründenstrasse 40, 4132, Muttenz, Switzerland.
authors.forename: Erik M
authors.initials: EM
authors.lastname: Ammann
authors.affiliation: Institute for Environmental Research, RWTH Aachen, Worringerweg 1, 52074, Aachen, Germany.|State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University Xianlin Campus, Xianlin Avenue 163, Nanjing, 210023, China.
authors.forename: Andreas
authors.initials: A
authors.lastname: Schäffer
authors.affiliation: Institute for Chemistry and Bioanalytics, School of Life Sciences, University of Applied Sciences and Arts Northwestern Switzerland, Gründenstrasse 40, 4132, Muttenz, Switzerland.
authors.forename: Patrick
authors.initials: P
authors.lastname: Shahgaldian
authors.affiliation: Institute for Ecopreneurship, School of Life Sciences, University of Applied Sciences and Arts Northwestern Switzerland, Gründenstrasse 40, 4132, Muttenz, Switzerland.|State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University Xianlin Campus, Xianlin Avenue 163, Nanjing, 210023, China.
authors.forename: Philippe F-X
authors.initials: PF
authors.lastname: Corvini
mesh_terms: D000085:Acetates / Q000737:chemistry; D000327:Adsorption; D055162:Biocatalysis; D018533:Biomass; D004800:Enzymes, Immobilized / Q000737:chemistry*; D005163:Factor Analysis, Statistical; D005561:Formates / Q000737:chemistry*; D005656:Fungal Proteins / Q000737:chemistry*; D042845:Laccase / Q000737:chemistry*; D008031:Lignin / Q000737:chemistry*; D058185:Magnetite Nanoparticles / Q000737:chemistry; D010084:Oxidation-Reduction; D014230:Triazoles / Q000737:chemistry
chemical_list: D000085:Acetates; D004800:Enzymes, Immobilized; D005561:Formates; D005656:Fungal Proteins; D058185:Magnetite Nanoparticles; D014230:Triazoles; C030544:formic acid; C007650:ethyl acetate; D008031:Lignin; C011852:1-hydroxybenzotriazole; D042845:Laccase
keywords: Biocatalysis; Depolymerization; Formic acid; Laccase; Lignin