Hollow silica nanotubes for immobilization of penicillin G acylase enzyme

In this study, porous hollow silica nanotubes (PHSNTs) synthesized via a sol-gel route using nano-sized needle-like CaCO3 the inorganic templates were employed as a support for immobilization of penicillin G acylase (PGA) biocatalyst. The produced PHSNTs were characterized by BET and transmission electron microscopy (TEM). Effect of various factors such as loading temperature and ratio of carries to free PGA (g/mL) on the catalytic activity of the immobilized PGA was also investigated by unitary factor testing method. The results show that under optimized conditions the relative loading amount and the total activity yield of immobilized enzyme (IME) amounts to 97.20% and 88.80%, respectively. Several advantages, i.e. the rapid immobilization of PGA onto PHSNTs, the high tolerability to the pH, the less sensitivity to the temperature and the improved storage stability render PHSNTs potential support materials for enzyme immobilization. (c) 2006 Elsevier B.V. All rights reserved.