In this study, an investigation was performed into the thermal and operational characteristics of glutaryl-7-aminocephalosporanic acid (GL-7-ACA) acylase (EC 3.5.1.-) immobilized on silica gel that had been modified by epoxide silanization. The pH values for the optimum activity of free and immobilized GL-7-ACA acylase were almost the same. However, the pH-dependent activity profile for the immobilized GL-7-ACA acylase is considerably expanded. Both free and immobilized enzymes generally had the highest activity at 50°C. In thermodynamic studies, it was found that immobilization using epoxide silanization made GL-7-ACA acylase thermodynamically stable. In the results of repeated batch production of 7-ACA, 89.0 and 83.5% of the 7-ACA produced at the initial cycle were maintained after 20 times of recycle at 25°C and 30°C, respectively. Hence it was suggested that mass production of 7-ACA at 25°C using immobilized GL-7-ACA acylase by epoxide silanization would be possible on a large scale.
- Epoxide silanization
- GL-7-ACA Acylase
- Repeated batch reaction
ASJC Scopus subject areas
- Applied Microbiology and Biotechnology