Enzymatic Reactions in Near Critical CO2: The Effect of Pressure on Phenol Removal by Tyrosinase

The use of enzymes in supercritical CO(2) (SCCO(2)) has received extensive attention in recent years. Biocatalysts have the advantage of substrate specificity and SCCO(2) offers several advantages over liquid solvents. This work deals with the utilization of SCCO(2) as a medium for the enzymatic removal of phenol from aqueous solutions using tyrosinase. Since the presence of oxygen is crucial for the enzyme-catalyzed oxidation, the substantial solvating power of SCCO(2) makes it a promising medium for such reactions. The conversion of phenol was higher at 10 MPa. Under near critical conditions (7 MPa, 35 degrees C), the addition of air at 5 x 10(5) Pa of pressure improved phenol removal.