Optimized oxidoreductases for medium and large scale industrial biotransformations
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Dr Marta Pérez-Boada
E-mail: MPBoada@cib.csic.es
Consejo Superior de Investigaciones Científicas (CSIC)
Biological Research Centre (CIB)
Calle Ramiro de Maeztu 9, E-28040 Madrid, Spain
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publications
Total records: 126
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[ 2015 ] Poraj-Kobielska M, Peter S, Leonhardt S, Ullrich R, Scheibner K, Hofrichter M Immobilization of unspecific peroxygenases (EC 1.11.2.1) in PVA/PEG gel and hollow fiber modules Biochem. Eng. J., 98: 144-150
[ 2015 ] Rico A, Rencoret J, del Río JC, Martínez AT, Gutiérrez A In-Depth 2D NMR Study of Lignin Modification During Pretreatment of Eucalyptus Wood with Laccase and Mediators Bioenerg. Res., 8: 211-230
[ 2015 ] Saez-Jimenez V, Acebes S, Guallar V, Martínez AT, Ruiz-Dueñas FJ Improving the oxidative stability of a high redox potential fungal peroxidase by rational design PlosOne, 10-4
[ 2015 ] Saez-Jimenez V, Baratto MC, Pogni R, Rencoret J, Gutiérrez A, Santos JI, Martínez AT, Ruiz-Dueñas FJ Demonstration of Lignin-to-Peroxidase Direct Electron Transfer: A Transient-state Kinetics, Directed Mutagenesis, EPR and NMR Study J. Biol. Chem., 290: 23201-23213
[ 2015 ] Saez-Jimenez V, Fernandez-Fueyo E, Medrano FJ, Romero A, Martínez AT, Ruiz-Dueñas FJ Improving the pH-stability of Versatile Peroxidase by Comparative Structural Analysis with a Naturally-Stable Manganese Peroxidase PlosOne, doi: 10.1371/journal.pone.0140984
[ 2015 ] Tan TC, Kracher D, Gandini R, Sygmund C, Kittl R, Haltrich D, Hällberg BM, Ludwig R, Divine C Structural basis for cellobiose dehydrogenase action during oxidative cellulose degradation Nat. Commun., 6: 7542
year2015
In-Depth 2D NMR Study of Lignin Modification During Pretreatment of Eucalyptus Wood with Laccase and Mediators
Rico A, Rencoret J, del Río JC, Martínez AT, Gutiérrez A
Bioenerg. Res., 8: 211-230

Eucalypt feedstock was pretreated with Myceliophthora thermophila laccase and methyl syringate, as mediator, in a multistage sequence consisting of successive enzymatic and alkaline peroxide stages, directly on the ground wood. Lignin modification was studied by two-dimensional (2D) nuclear magnetic resonance (NMR) of wood (at the gel state) after each stage of the sequence. Decrease of guaiacyl and syringyl lignin units (with preferential removal of the former) and aliphatic (mainly β-O-4′-linked) side chains was observed along the sequence, without a substantial change in polysaccharide cross-signals along the sequence, was observed. However, the most noticeable modification was the formation of Cα-oxidized syringyl units in the enzymatic stages, which were partially removed in the alkaline extractions. Further insight was attained by 2D NMR of the cellulolytic-enzyme lignins, isolated from the pretreated samples, and the filtrates from the different stages. Additionally, a comparison of eucalypt delignification with the high redox potential laccase from Pycnoporus cinnabarinus in the presence of the synthetic mediator 1-hydroxybenzotriazole was carried out. Wood delignification already occurred at the first cycle of the pretreatment with P. cinnabarinus laccase and 1-hydroxybenzotriazole, which directly correlated with increases in glucose (~10 %) yields after enzymatic hydrolysis. In contrast, the first cycle of pretreatment with M. thermophila laccase and methyl syringate did not produce any delignification or saccharification improvement. However, at the end of the sequence, similar delignification (~50 %) of eucalypt feedstock and increases (~30 %) in glucose yields were attained in both laccase-mediator pretreatments. Finally, the influence of lignin content and the ratio of its syringyl and guaiacyl units on recalcitrance of eucalypt feedstock to enzymatic saccharification is discussed.

Official webpage of indox [ industrialoxidoreductases ]. Optimized oxidoreductases for medium and large scale industrial biotransformations. This project has received funding from the European Union’s Seventh Framework Programme for research, technological development and demonstration under Grant Agreement nº: FP7-KBBE-2013-7-613549. © indox 2013. Developed by garcíarincón