Abstract

In order to modulate the microenvironment for enzyme covalently attached on support and improve the covalent immobilization of lipase, alcohol molecules were used to quench the excessive activated functional group on support surface. Effects of kind and content of alcohol molecules on the relative activity of the immobilized enzyme and the characteristics of the immobilized enzyme were examined carefully. The maximum relative activities of the immobilized lipase quenched with methanol and n-propanol, were 224.3 and 224.5%, respectively, both 1.96 fold of the just immobilized lipase which was not quenched with alcohol. Residual activity of the immobilized lipase using methanol to quench the excessive activated groups on support surface was 65.9% after heating at 50°C for 60 h, 1.29 folds higher than that of the ordinarily immobilized lipase (with no blockage). Alcohol molecules could alter the physical and chemical properties to modulate the microenvironment on support surface by changing the hydrophobicity. Suitable microenvironment, resulted from the methanol quenching the excessive active groups, would further favor the activity and the stability of lipase at higher temperature.

Key words: Alcohol quenching, mesocellular siliceous foams, covalent immobilization, microenvironment, lipase.

Abbreviation

MCFs, Mesocellular siliceous foams; GPTS, 3-glicydoxypropyltriethoxysilane; p-NPB, p-nitrophenyl acetate; FT-IR, fourier transform infrared.