Preparation of immobilized soybean β‐amylase on porous cellulose beads and continuous maltose production

Immobilized soybean β‐amylase was prepared by using porous cellulose beads. The expressed activity of the β‐amylase–cellulose beads conjugated below 35 mesh was 59–69% of the initial activity and the protein content was 10–13%. General properties of the conjugate were almost identical with those of the native enzyme except for the K m value. The K m value of the conjugate was 40m M and the K m value of the native enzyme was 0.6m M . This large difference was probably caused by pore structure, i.e., a pore diffusion problem. The film diffusion problem occurred at the flow rate below a linear velocity of 3 cm/min. Maximum maltose contents of the hydrolyzates prepared by the conjugate and the native enzyme were 69 and 71%, respectively. After a continuous column operation at 50°C for 17 days, the activity of the column was 60% of the activity. The half‐life of the column at 40°C was 40 days.