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The Termite Fungal Cultivar Termitomyces Combines Diverse Enzymes and Oxidative Reactions for Plant Biomass Conversion

Macrotermitine termites have domesticated fungi in the genus Termitomyces as their primary food source using predigested plant biomass. To access the full nutritional value of lignin-enriched plant biomass, the termite-fungus symbiosis requires the depolymerization of this complex phenolic polymer....

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Detalles Bibliográficos
Autores principales: Schalk, Felix, Gostinčar, Cene, Kreuzenbeck, Nina B., Conlon, Benjamin H., Sommerwerk, Elisabeth, Rabe, Patrick, Burkhardt, Immo, Krüger, Thomas, Kniemeyer, Olaf, Brakhage, Axel A., Gunde-Cimerman, Nina, de Beer, Z. Wilhelm, Dickschat, Jeroen S., Poulsen, Michael, Beemelmanns, Christine
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Society for Microbiology 2021
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8262964/
https://www.ncbi.nlm.nih.gov/pubmed/34126770
http://dx.doi.org/10.1128/mBio.03551-20
Descripción
Sumario:Macrotermitine termites have domesticated fungi in the genus Termitomyces as their primary food source using predigested plant biomass. To access the full nutritional value of lignin-enriched plant biomass, the termite-fungus symbiosis requires the depolymerization of this complex phenolic polymer. While most previous work suggests that lignocellulose degradation is accomplished predominantly by the fungal cultivar, our current understanding of the underlying biomolecular mechanisms remains rudimentary. Here, we provide conclusive omics and activity-based evidence that Termitomyces employs not only a broad array of carbohydrate-active enzymes (CAZymes) but also a restricted set of oxidizing enzymes (manganese peroxidase, dye decolorization peroxidase, an unspecific peroxygenase, laccases, and aryl-alcohol oxidases) and Fenton chemistry for biomass degradation. We propose for the first time that Termitomyces induces hydroquinone-mediated Fenton chemistry (Fe(2+) + H(2)O(2) + H(+) → Fe(3+) + (•)OH + H(2)O) using a herein newly described 2-methoxy-1,4-dihydroxybenzene (2-MH(2)Q, compound 19)-based electron shuttle system to complement the enzymatic degradation pathways. This study provides a comprehensive depiction of how efficient biomass degradation by means of this ancient insect’s agricultural symbiosis is accomplished.