Part of the solution may come from the production of fuel and chemicals from lignocellulose which comprise an abundant and cheap resource that does not compromise food security. Yet, the cost-efficient production of biofuels and materials or chemicals from lignocellulose is currently hampered by its natural recalcitrance. Consequently, the discovery of a new class of enzymes that boosts the degradation of polysaccharides has attracted considerable attention. This enzyme class is now termed lytic polysaccharide monooxygenases (LPMOs) and is currently grouped into eight families: AA9 to AA11 and AA13 to AA17. The LPMOs differ in substrate-specificity but they generally catalyze the oxidation of the glycosidic C-H bonds in the polysaccharide, leading ultimately to a cleavage of the glycosidic bond. This cleavage causes the boosting effect and is administered by a copper-containing active site with Cu coordinated by two histidines that has been coined the histidine brace. The active site with the histidine brace in the Cu(II)-resting state is shown in Fig. .