Sugar oxidoreductases and LPMOs-two sides of the same polysaccharide degradation story?

Lytic polysaccharide monooxygenases (LPMOs) catalyze the oxidative cleavage of glycosidic bonds in recalcitrant polysaccharides such as chitin and cellulose and their discovery has revolutionized our understanding of enzymatic biomass conversion. The discovery of LPMOs raises interesting new questions regarding the roles of other oxidoreductases and abiotic redox processes in biomass conversion. LPMOs need reducing power and an oxygen co-substrate and biomass degrading ecosystems contain a multitude of redox enzymes that affect the availability of both. For example, biomass degrading fungi produce multiple sugar oxidoreductases whose biological functions so far have remained somewhat enigmatic. It is now conceivable that these redox enzymes, in particular H2O2-producing sugar oxidases, could play a role in fueling and controlling LPMO reactions. Here, we shortly review contemporary issues in the LPMO field, paying particular attention to the possible roles of sugar oxidoreductases.

Automated summary

The discovery of lytic polysaccharide monooxygenases (LPMOs) has transformed our understanding of enzymatic biomass conversion, leading to questions about the roles of other oxidoreductases and abiotic redox processes. LPMOs require reducing power and an oxygen co-substrate, with biomass degrading ecosystems containing a variety of redox enzymes that influence their availability. It is now speculated that sugar oxidoreductases, particularly H2O2-producing sugar oxidases, may play a role in fueling and controlling LPMO reactions in biomass degrading fungi.