Characterization of 2 novel H2O2 producing glyoxal oxidases from Pycnoporus cinnabarinus implicated in the breakdown of lignocelluloses
Résumé
Lignin is one of the most abundant and recalcitrant natural polymers. Consequently, lignin degradation is important for completing the carbon cycle in forest ecosystems and a central challenge towards more environmentally-friendly and economically performing second-generation lignocellulosic-based biorefineries. The monokaryotic cell-line of the white-rot fungus Pycnoporus cinnabarinus BRFM 137 was shown to be an outstanding model to study the enzymatic machinery involved in the degradation and transformation of lignocellulosic materials [1]. Seven AA5_1 Carbohydrate-Active enzymes (Cazymes) have been identified including three glyoxal oxidases (GLOX) [2]. These GLOX are naturally secreted into the extracellular medium around the growing hyphal tip during fungal growth on lignin-rich substrates and acts as one of the sources of extracellular hydrogen peroxide that is mandatory for the oxidation reactions catalyzed by lignolytic peroxidases involved in lignin degradation [3]. In this work, two novel hydrogen peroxide-producing glyoxal oxidases from Pycnoporus cinnabarinus (PciGLOX1 and PciGLOX2) were for the first time cloned and successfully heterologously expressed in Aspergillus niger in Erlenmeyer flasks and in a 10 L bioreactor, and biochemically characterized. The wide variety of aldehydes that were oxidized makes these GLOX a promising tool not only for the deconstruction of plant biomass and the valorization of industrial lignin, but also for the production of valuable molecules for Green Chemistry applications. These enzymes and other oxidative enzymes produced in the framework of the EU-FP7 INDOX project will now be used simultaneously in order to study their synergistic interactions on lignocellulosic materials with the aim to get insights into the lignin-degrading strategies employed by Pycnoporus cinnabarinus.
Domaines
Biotechnologies
Fichier principal
Poster_Reims_2016_1.pdf (415.49 Ko)
Télécharger le fichier
Résumé_2.pdf (10.44 Ko)
Télécharger le fichier
Origine : Fichiers produits par l'(les) auteur(s)
Origine : Fichiers produits par l'(les) auteur(s)