**2.5 Optimum ratio of Pb-LPMO and Pb-ChiA during the hydrolysis of crystalline chitin**

Pb-LPMO (0.01, 0.1, 0.5, 1.0, 3.0, 5.0, 10, and 30 μM), 1 μM Pb-ChiA, and 1.0 mM ascorbic acid in 20 mM acetate buffer (pH 5.0) were incubated with α-chitin at 37°C for 24 h. After the reaction, the reaction mixture was boiled for 10 min to terminate the enzyme reaction. The samples were mixed with the same volume of acetonitrile. The resultant solution was applied onto a column of TSK-GEL Amide 80 (4.6 × 250 mm, Tosoh Co., Tokyo, Japan) and eluted with 70% acetonitrile at a flow rate of 0.7 mL/min, and the products were monitored by absorbance measurement at 210 nm. In this experiment, we estimated the concentration of GlcNAc, (GlcNAc)2, and total sugars (GlcNAc). The concentration of (GlcNAc)2 in total sugars was calculated as twice the concentration of GlcNAc.
