Abstract: In this paper, a novel inorganic crystal complex copper phosphate was used as a carrier to immobilize the lytic polysaccharide monooxygenase (cx-LPMO-B), the optimal conditions for immobilization of cx-LPMO-B was investigated, and the enzymatic properties were compared with the free and immobilization of cx-LPMO-B. The results showed that, copper sulfate was added to the pH=7.4 and 0.01 mol/L phosphate buffer solution containing the cx-LPMO-B to form immobilized cx-LPMO-B-copper phosphate nanoflowers, namely cx-LPMO-B-NF. The cx-LPMO-B-NF reached the highest immobilized yield at 25 ℃ for 14 h with the 0.3 g/L cx-LPMO-B. The immobilized cx-LPMO-B-NF retained a residual activity of approximately 60% after 6 cycles reaction. The nano structure of the immobilized cx-LPMO-B-NF was characterized with scanning electron microscope (SEM) and transmission electron microscope (TEM). It was performed that the immobilized cx-LPMO-B-NF was uniformly dispersed and single blooming flower shape. The optimal pH and temperature for immobilized cx-LPMO-B-NF were pH=4.0 and 50 ℃, respectively. The nano flower structure increased surface area of immobilized carrier to enhance cx-LPMO-B immobilization. Moreover, the reusability of immobilized cx-LPMO-B-NF was significantly enhanced.Therefore, the immobilized cx-LPMO-B-NF can promote advantages for cx-LPMO-B industrial application.

Key words: immobilization, nanoflower, lysing polysaccharide monooxygenase, enzymatic properties, inorganic crystal complex