Abstract:

Long-chain dialdehyde starch was linked to the surface of chitosan membrane to obtain an immobilization carrier for enzyme. Flexible immobilized papain was prepared through fixing papain on the carrier and applied to prepare small molecule peptide by hydrolyzing aphia undulate. The optimal immobilization conditions were explored by evaluating the effect of immobilization temperature, pH, enzyme amount and immobilization time on enzyme activity and recovery rate of flexible immobilized papain. Results indicated that the optimal immobilization conditions were reaction temperature of 25 ℃, reaction time of 20 h, enzyme amount of 40 mg/g, and pH 8.0. Under the optimal immobilization conditions, the obtained immobilized papain exhibited the highest activity and the recovery rate of papain was 63.35%.

Key words: chitosan, dialdehyde starch, immobilized enzyme