Enzymatic hydrolysis of p-nitrophenyl butyrate in CO2-based micelle systems

BACKGROUND: In this work, CO2-based micelles with TMN series surfactants were used as reactive medium. Hydrolysis of p-nitrophenyl butyrate catalyzed by porcine pancreas was used as a model reaction. The reactive behavior was used to optimize the reaction temperature, pH, pressure, enzyme concentration and the added water. RESULTS AND DISCUSSION: Generally, the reaction parameters depended on the types of substrates and enzymes. For the hydrolysis of p-nitrophenyl butyrate in CO2-basedmicelles, the reactive yield reached a high level at temperature 303 K, system pressure 15 MPa, pH 6.8, water to surfactant ratio W-0 15, and enzyme concentration 1 g mL(-1). In addition, the system reactivity was highest when TMN-6 surfactant was used. CONCLUSIONS: The activity of lipase-catalyzed hydrolysis in CO2-based micelle was increased significantly compared with that obtained in cyclohexane oil micelle. The combination of enzyme with supercritical CO2 represented a promising 'green' reaction system for bioconversions. (C) 2013 Society of Chemical Industry