Extracellular electron transfer systems fuel cellulose oxidative degradation
2016; American Association for the Advancement of Science; Volume: 352; Issue: 6289 Linguagem: Inglês
10.1126/science.aaf3165
ISSN1095-9203
AutoresDaniel Kracher, Stefan Scheiblbrandner, Alfons K. G. Felice, Erik Breslmayr, Marita Preims, Karolina Ludwicka, Dietmar Haltrich, Vincent G. H. Eijsink, Roland Ludwig,
Tópico(s)Lignin and Wood Chemistry
ResumoNinety percent of lignocellulose-degrading fungi contain genes encoding lytic polysaccharide monooxygenases (LPMOs). These enzymes catalyze the initial oxidative cleavage of recalcitrant polysaccharides after activation by an electron donor. Understanding the source of electrons is fundamental to fungal physiology and will also help with the exploitation of LPMOs for biomass processing. Using genome data and biochemical methods, we characterized and compared different extracellular electron sources for LPMOs: cellobiose dehydrogenase, phenols procured from plant biomass or produced by fungi, and glucose-methanol-choline oxidoreductases that regenerate LPMO-reducing diphenols. Our data demonstrate that all three of these electron transfer systems are functional and that their relative importance during cellulose degradation depends on fungal lifestyle. The availability of extracellular electron donors is required to activate fungal oxidative attack on polysaccharides.
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