Inactivation of LPMOs. The graphs show formation of C4-oxidized cellobiose, the by far dominant soluble oxidized product, during degradation of Avicel with the commercial cellulase cocktail Cellic CTec2. a Product formation in reactions containing 5 mM ascorbic acid and varying oxygen concentrations, showing that higher oxygen concentrations give higher rates and faster inactivation of LPMOs. b Product formation in anaerobic reactions containing 1 mM ascorbic acid, with feeding of H2O2. The feeding rate of H2O2 in μM/h is indicated in the Figure. Increasing amounts of H2O2 give faster rates and faster inactivation of the enzyme. The gradual decrease in product levels is due to the instability of the product.