Bioprocess Biosyst Eng. 2008 Aug;31(5):509-17. doi: 10.1007/s00449-007-0189-x. Epub 2008 Jan 04.
Bioprocess and biosystems engineering
Anming Wang, Hua Wang, Shemin Zhu, Cheng Zhou, Zhiqiang Du, Shubao Shen
To improve the performance of covalently immobilized penicillin acylase (PA), the immobilization was carried out in mesocellular silica foams (MCFs) using p-benzoquinone as cross linker. The characterizations of the immobilized enzyme were studied carefully. The results showed that the relative activity of the immobilized PA was increased to 145% of that of free enzyme. The activity was 3.7 folds of that of PA on the silica nanoparticles. The enzyme in MCFs presented a turnover equal to that of free enzyme. It was also found that the optimum pH of the immobilized PA shifted to pH 7.5 and the optimum reaction temperature rose from 45 to 50 degrees C. Furthermore, the stability of PA was ameliorated greatly after immobilization. Fourier transform infrared spectroscopy showed no major secondary structural change for PA confined in MCFs. The proposed covalent immobilizing technique would rank among the potential strategies for efficient immobilization of PA.