BerAbbreviations CI: compound I (of peroxidase catalytic cycle); CII: compound II (of peroxidase catalytic cycle); DHP: dehydrogenation polymer (in vitro synthesized lignin); DTT: dithiothreitol; EDTA: ethylenediaminetetraacetic acid; G: guaiacyl (lignin unit); HSQC: heteronuclear singlequantum correlation; k2 and k3: firstorder rate constants for CI and CII reduction, respectively; k2app and k3app: apparent secondorder price constants for CI and CII reduction, respectively; KD2 and KD3: equilibrium dissociation constants for CI and CII reduction, respectively; kobs: pseudofirstorder price constant; LiP: lignin peroxidase; LRET: longrange electron transfer; Mp: key peak (in SEC); NMR: nuclear magnetic resonance; PyGCMS: pyrolysisgas chromatographymass spectrometry; S: syringyl (lignin unit); SEC: sizeexclusion chromatography; VP: versatile peroxidase. Authors’ contributions VSJ and FJRD performed a lot of the biochemical experimental work and information analysis. JR performed the NMR study and sample derivatization. MARC con tributed optimization of lignosulfonate methylation. AG contributed chemical analyses. All authors contributed for the discussion of benefits, and critically revised the manuscript. VSJ and ATM wrote the paper. All authors read and authorized the final manuscript. Author particulars 1 CSIC, Centro de Investigaciones Biol icas, Ramiro de Maeztu 9, 28040 Madrid, Spain. 2 Department of Biology and Biological Engineering, Chalmers University of Technology, 41296 Gothenburg, Sweden. three CSIC, Instituto de Recursos Naturales y Agrobiolog de Sevilla, Avenida Reina Mer cedes 10, 41012 Seville, Spain. four Division of Organic Chemistry, University of Seville, Prof. Garc Gonz ez sn, 41012 Seville, Spain. Acknowledgements We thank Dr. Guro E. Fredheim (Borregaard AS, Sarpsborg, Norway) for provid ing the lignosulfonate preparations, and Dr. Manuel Angulo (CITIUS, University of Seville) for performing the NMR analyses. We acknowledge assistance with the publication fee by the CSIC Open Access Publication Support Initiative by means of its Unit of Details Sources for Research (URICI). Competing interests The authors declare that they have no competing interests. Funding This perform was supported by the INDOX (KBBE2013613549 to ATM) and EnzOx2 (H2020BBIPPP2015RIA720297 to ATM) EU projects, along with the NOESIS (BIO201456388R to FJRD), BIORENZYMERY (AGL201453730R to AG) and LIGNIN (CTQ201460764JIN to JR) projects from the Spanish Ministry of Economy and Competitiveness (MINECO) cofinanced by FEDER funds.References 1. Mart ez AT, RuizDue s FJ, Mart ez MJ, del R JC, Guti rez A. Enzy matic delignification of plant cell wall: from nature to mill. Curr Opin Biotechnol. 2009;20:3487. two. Bozell JJ, Petersen GR. Technologies improvement for the production of biobased merchandise from Alkaline fas Inhibitors targets biorefinery carbohydratesthe US Department of Energy’s “Top 10” revisited. Green Chem. 2010;12:5394. 3. Ragauskas AJ, Beckham GT, Biddy MJ, Chandra R, Chen F, Davis MF, Davison BH, Dixon RA, Gilna P, Keller M, Langan P, Naskar AK, Saddler JN, Tschaplinski T, Tuskan GA, Wyman CE. Lignin valorization: enhancing lignin processing within the biorefinery. Science. 2014;344:1246843. four. Pandey A, Hofer R, Larroche C, Taherzadeh M, Nampoothiri M. Industrial biorefineries and white biotechnology. Amsterdam: Elsevier; 2015. 5. Shahid M, Mohammad F, Chen G, Tang RC, Xing T. Enzymatic process ing of natural fibres: white biotechnology for sustainable improvement. Green Chem. 2016;18:22561. 6. Mart ez AT, Spe.