Biochemical studies on native and cross-linked aggregates of Aspergillus awamori feruloyl esterase.

Thermal stabilities of a native freeze dried Aspergillus awamori feruloyl esterase (FAE-II) enzyme and a cross-linked feruloyl esterase aggregate (CLEAs) at 25-85 degrees C were evaluated and discussed. Effects of some metal ions and some chemicals on the activity of both native freeze dried FAE-II enzyme and CLEAs were examined and explained. Differential scanning calorimetry, thermogravimetry, and derived thermogravimetry, were used to observe and explain the thermal denaturation processes. Structural analyses were made for native FAE-II and CLEAs using FT-IR and SEM techniques to investigate whether the cross-linking had any effect on the powder structure of native FAE-II enzyme.