Response to comment by Mueller et al.

This work described the preparation of silica gel modified with cyanuric chloride. The modified silica gel was tested for the ability to immobilize Burkholderia cepacia lipase. Contact times ranging from 4 to 24 h were investigated to determine the optimal lipase immobilization time. Following immobilization, the enzyme activity was assessed by the hydrolysis of p-nitrophenylpalmitate (pNPP). Elemental analysis data revealed that 0.4 mmol of cyanuric chloride were anchored per gram of support, demonstrating the successful incorporation of the triazine molecule onto the silica surface. The tests of reusability and storage indicated that the enzyme-modified silica-gel (immobilization at 24 h) was more stable under reaction conditions than the other systems. The activity assays indicated high rates of enzymatic formation of p-nitrophenol (p-NP), demonstrating a maximum activity retention of 87%.